Soy intake and risk of type 2 diabetes mellitus in Chinese Singaporeans

Purpose

To examine the association between soy products and their components, isoflavones and protein, and incident type 2 diabetes in a population with varied soy intake and high rates of diabetes.

Methods

We used data from the Singapore Chinese Health Study, including 43,176 Chinese men and women aged 45–74?years, free of chronic disease at baseline (1993–1998) and followed through 2004. Intake of individual soy items, total unsweetened soy, and soy components was assessed by food-frequency questionnaire and examined with type 2 diabetes risk using Cox regression.

Results

During an average follow-up of 5.7?years, 2,252 of the 43,176 participants included in the current analyses developed diabetes. After adjustment for potential confounders and BMI, consumption of unsweetened soy was inversely associated with diabetes risk. Hazard ratios (HRs) and 95% CI for diabetes across unsweetened soy intake categories (none, 1–4/month, 1–2/week, 3–4/week, ≥5/week) were: 1 (referent), 0.81 (0.67–0.97), 0.76 (0.63–0.91), 0.76 (0.63–0.92), and 0.72 (0.59–0.89), respectively (P _trend?=?0.015). Conversely, in multivariate models, consuming sweetened soybean drink was positively associated with diabetes risk. HRs for diabetes across soybean drink intake categories (none, 1–3/month, 1/week, ≥2/week) were: 1 (referent), 1.07 (0.95–1.20), 1.12 (1.00–1.26), and 1.13 (1.00–1.28), respectively (P _trend?=?0.03). Furthermore, after full adjustment, including adjustment for sweetened soy items, we observed a marginally significant inverse association between isoflavone intake and diabetes (HR for the fifth compared to the first quintile: 0.76; 95% CI: 0.58–1.00; P _trend?=?0.08).

Conclusions

The current findings support a protective role for unsweetened soy foods and isoflavones on risk of type 2 diabetes.     

Association Between Sugar-Sweetened Beverage Intake and Mortality Risk in Women: The California Teachers Study

BackgroundThe evidence linking sugar-sweetened beverage (SSB) intake and mortality risk is conflicting, and associations between various SSB subtypes and mortality remain unclear.ObjectiveTo examine the association between baseline SSB intake, subtypes of SSB intake, and mortality risk in women.DesignProspective cohort study.Participants/settingParticipants of the California Teachers Study (n = 100,314; median age = 53 years) free of cardiovascular disease, cancer, and diabetes at baseline (1995-1996) were followed from 1995 to 2015. Baseline SSB intake was defined as caloric soft drinks (regular soft drinks, not diet soda), sweetened bottled waters or teas, and fruit drinks; and was derived from a self-administered food frequency questionnaire.Main outcome measureMortality was ascertained via annual linkage with state- and nationwide mortality records and the National Death Index over 20 years.Statistical analysisMultivariable-adjusted Cox proportional hazards models were used to generate hazard ratios (HRs) and 95% CIs for assessing associations between SSB intake and mortality. Rare/never consumers were the comparator group.ResultsThere were a total of 14,143 deaths over 20 years (30.5% from cardiovascular disease; 29.2% from cancer). In women who consumed ≥ 7 servings/week of SSBs at baseline (4% of participants), the multivariable-adjusted HRs were not significant for all-cause, cardiovascular disease-specific, or cancer-specific mortality. Consuming ≥ 7 servings/week of baseline caloric soft drink was associated with a higher risk of all-cause (HR = 1.26, 95% CI 1.10 to 1.46; P for trend = 0.02) and cancer-specific (HR = 1.33, 95% CI 1.08 to 1.63; P for trend = 0.08) mortality. In secondary analyses, consuming ≥ 1.5 c/day of baseline SSBs was associated with all-cause mortality (HR = 1.12, 95% CI 1.02 to 1.24; P for trend = 0.01).ConclusionsAlthough the baseline frequency of total SSB intake was not significantly associated with mortality, consuming ≥ 7 servings/week of caloric soft drinks was associated with higher risk of all-cause and cancer-specific mortality. Findings support public health efforts to reduce caloric soft drink consumption.     

Differential effect of obesity on bone mineral density in White, Hispanic and African American women: a cross sectional study

Background

The low-carbohydrate, ketogenic diet (LCKD) may be effective for improving glycemia and reducing medications in patients with type 2 diabetes.

Methods

From an outpatient clinic, we recruited 28 overweight participants with type 2 diabetes for a 16-week single-arm pilot diet intervention trial. We provided LCKD counseling, with an initial goal of <20 g carbohydrate/day, while reducing diabetes medication dosages at diet initiation. Participants returned every other week for measurements, counseling, and further medication adjustment. The primary outcome was hemoglobin A_1c.

Results

Twenty-one of the 28 participants who were enrolled completed the study. Twenty participants were men; 13 were White, 8 were African-American. The mean [± SD] age was 56.0 ± 7.9 years and BMI was 42.2 ± 5.8 kg/m². Hemoglobin A_1c decreased by 16% from 7.5 ± 1.4% to 6.3 ± 1.0% (p < 0.001) from baseline to week 16. Diabetes medications were discontinued in 7 participants, reduced in 10 participants, and unchanged in 4 participants. The mean body weight decreased by 6.6% from 131.4 ± 18.3 kg to 122.7 ± 18.9 kg (p < 0.001). In linear regression analyses, weight change at 16 weeks did not predict change in hemoglobin A_1c. Fasting serum triglyceride decreased 42% from 2.69 ± 2.87 mmol/L to 1.57 ± 1.38 mmol/L (p = 0.001) while other serum lipid measurements did not change significantly.

Conclusion

The LCKD improved glycemic control in patients with type 2 diabetes such that diabetes medications were discontinued or reduced in most participants. Because the LCKD can be very effective at lowering blood glucose, patients on diabetes medication who use this diet should be under close medical supervision or capable of adjusting their medication.     

The impact of new screen-detected and previously known type 2 diabetes on health-related quality of life: a population-based study in Qingdao,China

Aims

To examine and compare health-related quality of life (HRQoL) in people with previously known diabetes, new screen-detected asymptomatic diabetes and people without diabetes.

Methods

HRQoL of 4,613 individuals who participated in a population-based cross-sectional diabetes survey in Qingdao, China, in 2009, was assessed using the 15D instrument. A Tobit regression model to estimate the effects of diabetes on HRQoL separate from effects of other health determinants was constructed.

Results

Among the surveyed population, 220 (4.8 %) individuals had previously known diabetes and 531 (11.5 %) individuals had new screen-detected diabetes, defined by fasting plasma glucose ≥7.0 mmol/l and/or 2-h plasma glucose ≥11.1 mmol/l. The age-, gender-, and BMI-adjusted mean 15D score of people without diabetes, with new screen-detected diabetes, and previously known diabetes was 0.975, 0.975, and 0.964, respectively, for urban and 0.971, 0.972, and 0.960, respectively, for rural participants. HRQoL overall and on all the dimensions (p < 0.05) except for hearing, eating, and speech was worse in the people with previously known diabetes compared to those with new screen-detected diabetes and those without diabetes. Compared to people without diabetes, people with new screen-detected diabetes were worse off on the dimension of usual activities (p < 0.05). After adjusting for comorbid diseases and other confounders, the impact of diabetes on reduced HRQoL was diminished.

Conclusion

Health-related quality of life was impaired in people with previously known diabetes who had co-morbid conditions, but was largely unaltered in people with newly detected asymptomatic diabetes as compared to people without diabetes.     

Effect of using repeated measurements of a Mediterranean style diet on the strength of the association with cardiovascular disease during 12 years: the Doetinchem Cohort Study

Background

In cohort studies, often only one baseline measurement of dietary intake is available. This may underestimate the strength of the association with cardiovascular diseases (CVD).

Objective

The main objective is to compare the strength of the association of a Mediterranean style diet with CVD using one baseline measurement of diet versus three repeated measurements over a 10-year period.

Design

We used dietary and lifestyle data of three rounds of the Doetinchem Cohort Study. At baseline, 7,769 persons aged 20–65 years were examined. Diet was assessed with a 178 item validated food-frequency questionnaire and operationalized with the Mediterranean Diet Score (MDS) ranging from 0 to 9. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CI). Analyses were adjusted for age, sex, and repeated measurements of smoking, sports, total energy intake, and educational level.

Results

Comparing an MDS of ≥5.5–9 to an MDS of 0–<3.5, baseline MDS was associated with a 23 % lower risk [HR 0.77 (95 % CI 0.53–1.11)] and the updated mean with a 35 % lower risk [HR 0.65 (0.43–0.97)] of a composite of fatal CVD, nonfatal myocardial infarction, and stroke (composite CVD). For fatal CVD, baseline MDS was associated with a 13 % lower risk [HR 0.87 (0.36–2.07)] and the updated mean with a 56 % lower risk [HR 0.44 (0.19–1.05)].

Conclusion

The strength of the association between a Mediterranean style diet and CVD is likely underestimated because most studies so far used only one baseline measurement.     

The association between state bans on soda only and adolescent substitution with other sugar-sweetened beverages: a cross-sectional study

Background

Across the United States, many states have actively banned the sale of soda in high schools, and evidence suggests that students’ in-school access to soda has declined as a result. However, schools may be substituting soda with other sugar-sweetened beverages (SSBs), and national trends indicate that adolescents are consuming more sports drinks and energy drinks. This study examined whether students consumed more non-soda SSBs in states that banned the sale of soda in school.

Methods

Student data on consumption of various SSBs and in-school access to vending machines that sold SSBs were obtained from the National Youth Physical Activity and Nutrition Study (NYPANS), conducted in 2010. Student data were linked to state laws regarding the sale of soda in school in 2010. Students were cross-classified based on their access to vending machines and whether their state banned soda in school, creating 4 comparison groups. Zero-inflated negative binomial models were used to compare these 4 groups with respect to students’ self-reported consumption of diet soda, sports drinks, energy drinks, coffee/tea, or other SSBs. Students who had access to vending machines in a state that did not ban soda were the reference group. Models were adjusted for race/ethnicity, sex, grade, home food access, state median income, and U.S. Census region.

Results

Students consumed more servings of sports drinks, energy drinks, coffee/tea, and other SSBs if they resided in a state that banned soda in school but attended a school with vending machines that sold other SSBs. Similar results were observed where schools did not have vending machines but the state allowed soda to be sold in school. Intake was generally not elevated where both states and schools limited SSB availability – i.e., states banned soda and schools did not have SSB vending machines.

Conclusion

State laws that ban soda but allow other SSBs may lead students to substitute other non-soda SSBs. Additional longitudinal research is needed to confirm this. Elevated SSB intake was not observed when both states and schools took steps to remove SSBs from school.

     

Fructo-oligosaccharide attenuates the production of pro-inflammatory cytokines and the activation of JNK/Jun pathway in the lungs of d-galactose-treated Balb/cJ mice

Purpose

This study determined the effects of long-term d-galactose (DG) injection on the lung pro-inflammatory and fibrotic status and whether fructo-oligosaccharide (FO) could attenuate such effects.

Methods

Forty Balb/cJ mice (12 weeks of age) were divided into four groups: control (s.c. saline) (basal diet), DG (s.c. 1.2 g DG/kg body weight) (basal diet), DG + FO (FO diet, 2.5 % w/w FO), and DG + E (vitamin E diet, α-tocopherol 0.2 % w/w) serving as an antioxidant control group. These animals were killed after 49 day of treatments. Another group of naturally aging (NA) mice without any injection was killed at 64 weeks of age to be an aging control group.

Results

d-galactose treatment, generally similar to NA, increased the lung pro-inflammatory status, as shown in the IL-6 and IL-1β levels and the expression of phospho-Jun and phospho-JNK, and the fibrotic status as shown in the hydroxyproline level compared to the vehicle. FO diminished the DG-induced increases in the lung IL-1β level and expressions of total Jun, phospho-JNK, and attenuated DG effects on lung IL-6 and hydroxyproline, while α-tocopherol exerted anti-inflammatory effects on all parameters determined. FO, as well as α-tocopherol, modulated the large bowel ecology by increasing the fecal bifidobacteria and cecal butyrate levels compared with DG.

Conclusions

d-galactose treatment mimicked the lung pro-inflammatory status as shown in the NA mice. FO attenuated the DG-induced lung pro-inflammatory status and down-regulated JNK/Jun pathway in the lung, which could be mediated by the prebiotic effects and metabolic products of FO in the large intestine.     

Adaptive metabolic response to 4 weeks of sugar-sweetened beverage consumption in healthy, lightly active individuals and chronic high glucose availability in primary human myotubes

Purpose

Chronic sugar-sweetened beverage (SSB) consumption is associated with obesity and type 2 diabetes mellitus (T2DM). Hyperglycaemia contributes to metabolic alterations observed in T2DM, such as reduced oxidative capacity and elevated glycolytic and lipogenic enzyme expressions in skeletal muscle tissue. We aimed to investigate the metabolic alterations induced by SSB supplementation in healthy individuals and to compare these with the effects of chronic hyperglycaemia on primary muscle cell cultures.

Methods

Lightly active, healthy, lean subjects (n = 11) with sporadic soft drink consumption underwent a 4-week SSB supplementation (140 ± 15 g/day, ~2 g glucose/kg body weight/day, glucose syrup). Before and after the intervention, body composition, respiratory exchange ratio (RER), insulin sensitivity, muscle metabolic gene and protein expression were assessed. Adaptive responses to hyperglycaemia (7 days, 15 mM) were tested in primary human myotubes.

Results

SSB supplementation increased fat mass (+1.0 kg, P < 0.05), fasting RER (+0.12, P < 0.05), fasting glucose (+0.3 mmol/L, P < 0.05) and muscle GAPDH mRNA expressions (+0.94 AU, P < 0.05). PGC1α mRNA was reduced (?0.20 AU, P < 0.05). Trends were found for insulin resistance (+0.16 mU/L, P = 0.09), and MondoA protein levels (+1.58 AU, P = 0.08). Primary myotubes showed elevations in GAPDH, ACC, MondoA and TXNIP protein expressions (P < 0.05).

Conclusion

Four weeks of SSB supplementation in healthy individuals shifted substrate metabolism towards carbohydrates, increasing glycolytic and lipogenic gene expression and reducing mitochondrial markers. Glucose-sensing protein MondoA might contribute to this shift, although further in vivo evidence is needed to corroborate this.     

Accounting for increased non-target-disease-specific mortality in decision-analytic screening models for economic evaluation

Background

Positive screening results are often associated not only with target-disease-specific but also with non-target-disease-specific mortality. In general, this association is due to joint risk factors. Cost-effectiveness estimates based on decision-analytic models may be biased if this association is not reflected appropriately.

Objective

To develop a procedure for quantifying the degree of bias when an increase in non-target-disease-specific mortality is not considered.

Methods

We developed a family of parametric functions that generate hazard ratios (HRs) of non-target-disease-specific mortality between subjects screened positive and negative, with the HR of target-disease-specific mortality serving as the input variable. To demonstrate the efficacy of this procedure, we fitted a function within the context of coronary artery disease (CAD) risk screening, based on HRs related to different risk factors extracted from published studies. Estimates were embedded into a decision-analytic model, and the impact of ‘modelling increased non-target-disease-specific mortality’ was assessed.

Results

In 55-year-old German men, based on a risk screening with 5 % positively screened subjects, and a CAD risk ratio of 6 within the first year after screening, incremental quality-adjusted life–years were 19 % higher and incremental costs were 8 % lower if no adjustment was made. The effect varied depending on age, gender, the explanatory power of the screening test and other factors.

Conclusion

Some bias can occur when an increase in non-target-disease-specific mortality is not considered when modelling the outcomes of screening tests.     

Association between diet quality with concurrent vision and hearing impairment in older adults

Objectives

Published literature shows that individual nutrients could influence the risk of developing vision and hearing loss. There is, however, a lack of population-based data on the relationship between overall patterns of food intake and the presence of concurrent vision and hearing impairment. We aimed to assess the associations between diet quality with the prevalence and 5-year incidence of dual sensory impairment (DSI).

Design

Cross-sectional and 5-year longitudinal analyses.

Setting

Blue Mountains, Sydney, Australia.

Participants

2443 participants aged ≥50 from baseline were examined and followed over 5 years.

Measurements

Dietary data were collected using a semi-quantitative food frequency questionnaire. A modified version of the Healthy Eating Index for Australians was developed to determine total diet score (TDS). Visual impairment was defined as visual acuity less than 20/40 (better eye), and hearing impairment as average pure-tone air conduction threshold greater than 25 dB HL (500–4000 Hz, better ear).

Results

After adjusting for age, sex, education, noise exposure, current smoking, and type 2 diabetes, participants in the lowest compared to the highest quintile of TDS had a 2-fold increased likelihood of having prevalent DSI, odds ratio, OR, 2.62 (95% confidence intervals, CI, 1.08–6.36), P-trend=0.04. Significant associations were not observed between TDS and the prevalence of having a single sensory impairment (vision or hearing loss). Baseline TDS was not significantly associated with the 5-year incidence of DSI. Adherence to dietary guidelines was associated with a reduced likelihood of having DSI in cross-sectional, but not in longitudinal analyses.

Conclusions

Further studies with adequate power are warranted to assess the prospective relationship between diet quality and DSI.     

Fluid intake of children,adolescents and adults in Indonesia: results of the 2016 Liq.In<Superscript>7</Superscript> national cross-sectional survey

Purpose

To report daily total fluid intake (TFI) and fluid types in Indonesia according to age, sex, socio-economic status (SES) and geographic region, and compare TFI with the Indonesian adequate fluid intake (AI) recommendations.

Methods

Data were collected in 32 cities over nine regions from children (4–9 years, n?=?388), adolescents, (10–17 years, n?=?478) and adults (18–65 years, n?=?2778) using a fluid intake 7-day record (Liq.In⁷); socio-economic status was also recorded. The 7-day mean TFIs were compared with the AI of water set by the Ministry of Health of the Republic of Indonesia.

Results

Total median fluid intakes for all age groups exceeded 2000 mL/day. At population level, TFI was associated with household income (P?<?0.001), education (P?<?0.001) and Indonesian geographical regions (P?<?0.001). More than 67% of participants met the AI of water from fluids. A higher percentage of children and adolescents met the AI (78 and 80%, respectively), compared with adults (72%). Drinking water was the main contributor to TFI in all age groups (76–81%). Sugar-sweetened beverages (SSB) were consumed by 62% children, 72% adolescents and 61% of adults. An SSB intake?≥?1 serving per day was observed for 24% children, 41% adolescents and 33% adults.

Conclusions

A high percentage of the population drank enough to meet the AI of water from fluids. Water was the most frequently consumed drink; however, many participants consumed at least one serving of SSB per day. This study provides data to help direct targeted intervention programs.

     

Fluid intake in urban China: results of the 2016 <Emphasis Type="Italic">Liq.In</Emphasis><Superscript><Emphasis Type="Italic">7</Emphasis></Superscript> national cross-sectional surveys

Purpose

To describe total fluid intake (TFI) and types of fluid consumed in urban China by age, gender, regions and city socioeconomic status relative to the adequate intakes (AI) set by the Chinese Nutrition Society.

Methods

In 2016, participants aged 4–9, 10–17 and 18–55 years were recruited via a door-to-door approach in 27 cities in China. In total, 2233 participants were included. The volumes and sources of TFI were collected using the Liq.In ⁷ record, assisted by a photographic booklet of standard fluid containers.

Results

The mean daily TFI among children, adolescents and adults were 966, 1177 and 1387 mL, respectively. In each age group, TFI was significantly higher in male vs female (981 vs 949, 1240 vs 1113, 1442 vs 1332; mL). Approximately 45, 36 and 28% of children, adolescents and adults reached the AI. Although plain water was the highest contributor to TFI, the contribution of sugar sweetened beverages (SSB) was ranked in the top three together with water and milk and derivatives. Approximately 27, 48 and 47% of children, adolescents and adults consumed more than one serving of SSB per day, respectively.

Conclusions

A relatively large proportion of participants did not drink enough to meet the AI in urban China. Many children, adolescents and adults consumed more than one serving of SSB per day. A majority of children, adolescents and adults in the study population do not meet both quantitative and qualitative fluid intake requirements, and signal socioeconomic disparities.

     

Impact of diagnosis of diabetes on health-related quality of life among high risk individuals: the Diabetes Prevention Program outcomes study

Purpose

The purpose of this study is to assess if diagnosis of type 2 diabetes affected health-related quality of life (HRQoL) among participants in the Diabetes Prevention Program/Diabetes Prevention Program Outcome Study and changes with treatment or diabetes duration.

Methods

3,210 participants with pre-diabetes were randomized to metformin (MET), intensive lifestyle intervention (ILS), or placebo (PLB). HRQoL was assessed using the SF-36 including: (1) 8 SF-36 subscales; (2) the physical component (PCS) and mental component summary (MCS) scores; and (3) the SF-6D. The sample was categorized by diabetes free versus diagnosed. For diagnosed subgroup, mean scores in the diabetes-free period, at 6 months, 2, 4 and 6 years post-diagnosis, were compared.

Results

PCS and SF-6D scores declined in all participants in all treatment arms (P < .001). MCS scores did not change significantly in any treatment arm regardless of diagnosis. ILS participants reported a greater decrease in PCS scores at 6 months post-diagnosis (P < .001) and a more rapid decline immediately post-diagnosis in SF-6D scores (P = .003) than the MET or PLB arms. ILS participants reported a significant decrease in the social functioning subscale at 6 months (P < .001) and two years (P < .001) post-diagnosis.

Conclusions

Participants reported a decline in measures of overall health state (SF-6D) and overall physical HRQoL, whether or not they were diagnosed with diabetes during the study. There was no change in overall mental HRQoL. Participants in the ILS arm with diabetes reported a more significant decline in some HRQoL measures than those in the MET and PLB arms that developed diabetes.     

The effect of almonds on inflammation and oxidative stress in Chinese patients with type 2 diabetes mellitus: a randomized crossover controlled feeding trial

Purpose

Almond consumption is associated with ameliorations in obesity, hyperlipidemia, hypertension, and hyperglycemia. The hypothesis of this 12-week randomized, crossover, controlled feeding trial was that almond consumption would ameliorate inflammation and oxidative stress in Chinese patients with type 2 diabetes mellitus (T2DM) (9 M, 11 F; 58 years; BMI: 26 kg/m²) with mild hyperlipidemia.

Methods

After a 2-week run-in period, the patients were assigned to either a control NCEP step II diet (control diet) or almond diet for 4 weeks with a 2-week washout period between alternative diets. Almonds approximately at 56 g/day were added to the control diet to replace 20 % of total daily calorie intake.

Results

As compared to the control diet, the almond diet decreased IL-6 by a median 10.3 % (95 % confidence intervals 5.2, 12.6 %), CRP by a median 10.3 % (?24.1, 40.5), and TNF-α by a median 15.7 % (?0.3, 29.9). The almond diet also decreased plasma protein carbonyl by a median 28.2 % (4.7, 38.2) as compared to the C diet but did not alter plasma malondialdehyde. The A diet enhanced the resistance of LDL against Cu²⁺-induced oxidation by a median 16.3 % (7.4, 44.3) as compared to the C diet. Serum intercellular adhesion molecule-1 and vascular adhesion molecule-1 were not changed by both diets.

Conclusions

Our results suggested that incorporation of almonds into a healthy diet could ameliorate inflammation and oxidative stress in patients with T2DM.     

Determinants of quality of life in children with chronic somatic disease: pilot data from the GapS Questionnaire

Purpose

Quality of life (QoL) is a ubiquitous yet poorly defined concept; the precise determinants of QoL are rarely identified. We used pilot data from the GapS Questionnaire to investigate the most important determinants of QoL in children with chronic somatic illness.

Methods

We enrolled 92 participants including 60 parents and 32 of their children. The sample comprised rheumatology, diabetes, epilepsy, gastroenterology, cystic fibrosis, and day unit patients. Trained interviewers administered the GapS Questionnaire to parents, and to children if ≥10 years. We determined the relative importance of different items for QoL.

Results

Child participants had a mean age of 14.7 years. Children identified “having good friendships”, “being happy most days”, and “getting along with parents” as most important. Parents ranked most highly “being allowed to do all the things you like doing”, “getting told you have done a good job at something”, and “being physically able to do everything you enjoy doing”.

Conclusions

Physical health items were not as important as social and psychological determinants of QoL in our pilot sample.     

Effects of l-arginine supplementation on blood flow, oxidative stress status and exercise responses in young adults with uncomplicated type I diabetes

Background and aims

Vascular disease is the principal cause of death and disability in patients with diabetes, and endothelial dysfunction seems to be the major cause in its pathogenesis. Since l-arginine levels are diminished in conditions such as type 1 and type 2 diabetes, in this work we aimed to verify the effects of l-arginine supplementation (7 g/day) over the endothelial function and oxidative stress markers in young male adults with uncomplicated type 1 diabetes. We also investigated the influences of l-arginine administration on vascular/oxidative stress responses to an acute bout of exercise.

Methods

Ten young adult male subjects with uncomplicated type 1 diabetes and twenty matched controls volunteered for this study. We analysed the influence of l-arginine supplementation (7 g/day during 1 week) over lower limb blood flow (using a venous occlusion plethysmography technique), oxidative stress marker (TBARS, Carbonyls), anti-oxidant parameters (uric acid and TRAP) and total tNOx in rest conditions and after a single bout of submaximal exercise (VO₂ at 10 % below the second ventilatory threshold). Data described as mean ± standard error (SE). Alpha level was P < 0.05.

Results

Glycaemic control parameters were altered in type 1 diabetic subjects, such as HbA1c (5.5 ± 0.03 vs. 8.3 ± 0.4 %) and fasted glycaemia (94.8 ± 1.4 vs. 183 ± 19 mg/dL). Oxidative stress/damage markers (carbonyls and TBARS) were increased in the diabetic group, while uric acid was decreased. Rest lower limb blood flow was lower in type 1 diabetic subjects than in healthy controls (3.53 ± 0.35 vs. 2.66 ± 0.3 ml 100 ml^?¹ min^?¹). l-Arginine supplementation completely recovered basal blood flow to normal levels in type 1 diabetics’ subjects (2.66 ± 0.3 to 4.74 ± 0.86 ml 100 ml^?¹ min^?¹) but did not interfere in any parameter of redox state or exercise.

Conclusion

Our findings highlight the importance of l-arginine for the improvement of vascular function in subjects with diabetes, indicating that l-arginine supplementation could be an essential tool for the treatment for the disease complications, at least in non-complicated diabetes. However, based on our data, it is not possible to draw conclusions regarding the mechanisms by which l-arginine therapy is inducing improvements on cardiovascular function, but this important issue requires further investigations.     

Ellagic acid attenuates high-carbohydrate, high-fat diet-induced metabolic syndrome in rats

Background

Fruits and nuts may prevent or reverse common human health conditions such as obesity, diabetes and hypertension; together, these conditions are referred to as metabolic syndrome, an increasing problem. This study has investigated the responses to ellagic acid, present in many fruits and nuts, in a diet-induced rat model of metabolic syndrome.

Methods

Eight- to nine-week-old male Wistar rats were divided into four groups for 16-week feeding with cornstarch diet (C), cornstarch diet supplemented with ellagic acid (CE), high-carbohydrate, high-fat diet (H) and high-carbohydrate, high-fat diet supplemented with ellagic acid (HE). CE and HE rats were given 0.8 g/kg ellagic acid in food from week 8 to 16 only. At the end of 16 weeks, cardiovascular, hepatic and metabolic parameters along with protein levels of Nrf2, NF-κB and CPT1 in the heart and the liver were characterised.

Results

High-carbohydrate, high-fat diet-fed rats developed cardiovascular remodelling, impaired ventricular function, impaired glucose tolerance, non-alcoholic fatty liver disease with increased protein levels of NF-κB and decreased protein levels of Nrf2 and CPT1 in the heart and the liver. Ellagic acid attenuated these diet-induced symptoms of metabolic syndrome with normalisation of protein levels of Nrf2, NF-κB and CPT1.

Conclusions

Ellagic acid derived from nuts and fruits such as raspberries and pomegranates may provide a useful dietary supplement to decrease the characteristic changes in metabolism and in cardiac and hepatic structure and function induced by a high-carbohydrate, high-fat diet by suppressing oxidative stress and inflammation.     

Postprandial glucose, insulin and gastrointestinal hormones in healthy and diabetic subjects fed a fructose-free and resistant starch type IV-enriched enteral formula

Background

Reducing the dietary glycaemic response has been proposed as a means of reducing the risk of diabetes.

Aim

To evaluate the effects of a new diabetes-specific formula (DSF) enriched with resistant starch type IV and fructose-free on postprandial glycaemia, insulinaemia and gastrointestinal hormones in healthy volunteers and in outpatient type 2 diabetics.

Methods

(1) Twenty-four healthy volunteers were divided into two groups: Group 1 ( n = 10) was provided 50 g of the carbohydrate (CHO) constituent of the new product and 50 g of glucose separated by 1 week; Group 2 ( n = 14) was provided 400 ml of the new DSF (T-Diet Plus^® Diabet NP) and 400 ml of a control product separated by 1 week. (2) Ten type 2 diabetic patients received 400 ml of the new DSF and two other commercially available DSF (Glucerna^® SR and Novasource^® Diabet) on three occasions separated by 1 week. Venous blood samples were drawn at time 0 and at different times until 120 min. Glucose, insulin and gastrointestinal hormones were determined. Glycaemic and insulinaemic indices and glycaemic load were calculated.

Results

The CHO constituent and the new DSF showed low glycaemic index and glycaemic load. In healthy subjects, insulin and C-peptide release were lower after administration of the CHO constituent as well as after the new DSF (P < 0.001). Ghrelin, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) production were lower after intake of the CHO constituent (P ranging from <0.001 to 0.019) compared with glucose, and GIP was lower after ingestion of the new DSF (P = 0.002) than after the control product. In type 2 diabetic patients, glucose AUC was lower after the administration of the new DSF (P = 0.037) compared with the others.

Conclusions

Our results indicate that this new product could be beneficial for diabetic patients.     

Direct effects of leisure-time physical activity on walking speed

Objective

This study quantifies the effects of leisure-time physical activity (LTPA) on walking speed independently of body composition in an elderly cohort, and in those elderly with metabolic derangements due to age, diabetes, and cardiovascular disease (CVD).

Methods

1655 community-dwelling women and men >55 years were measured for body composition (lean mass: fat mass ratio, LNFAT), based on estimated bioelectric impedance by using population-specific prediction equations derived from dual-energy x-ray absorptiometry. In addition to LNFAT, LTPA, diabetes, CVD, walking speed, and other covariates were measured biannually over an 8-year period. LTPA was categorized as <22.5 Mets/week, ≥ 22.5 Mets/week, based on public-health recommended guidelines, and LNFAT was dichotomized based on its sex-specific median. Direct effects of high vs. low LTPA on walking speed were estimated for fixed levels of LNFAT, which represented an intermediary variable in the analysis. Stratified estimates of effects were obtained using subject status (e.g., age≥75 years, diabetes, CVD) at each visit.

Results

Walking speed was significantly greater (0.74, 0.75 m/s in women and men, respectively) if subjects experienced LTPA ≥22.5 Mets/week and > median LNFAT, compared with <22.5 Mets/week and ≤ median LNFAT (0.68, 0.69 m/s). While direct effects of LTPA contributed to higher walking speed, none were significant in the overall, nor the stratified groups of subjects, of either sex.

Conclusions

Walking speed increases with greater LTPA and LNFAT in the elderly, but there was no evidence to indicate that walking speed increases from LTPA independently of body composition and the metabolic processes it represents.     

Serum sterol responses to increasing plant sterol intake from natural foods in the Mediterranean diet

Background

Phytosterols in natural foods are thought to inhibit cholesterol absorption. The Mediterranean diet is rich in phytosterol-containing plant foods.

Aim of the study

To assess whether increasing phytosterol intake from natural foods was associated with a cholesterol-lowering effect in a substudy of a randomized trial of nutritional intervention with Mediterranean diets for primary cardiovascular prevention (PREDIMED study).

Methods

One hundred and six high cardiovascular risk subjects assigned to two Mediterranean diets supplemented with virgin olive oil (VOO) or nuts, which are phytosterol-rich foods, or advice on a low-fat diet. Outcomes were 1-year changes in nutrient intake and serum levels of lipids and non-cholesterol sterols.

Results

Average phytosterol intake increased by 76, 158 and 15 mg/day in participants assigned VOO, nuts and low-fat diets, respectively. Compared to participants in the low-fat diet group, changes in outcome variables were observed only in those in the Mediterranean diet with nuts group, with increases in intake of fibre, polyunsaturated fatty acids and phytosterols (P < 0.020, all) and significant (P < 0.05) reductions of LDL-cholesterol (0.27 mmol/l or 8.3%) and the LDL/HDL-cholesterol ratio (0.29 mmol/l or 11.5%). Variations in saturated fat, cholesterol or fibre intake were unrelated to LDL-cholesterol changes. In the whole group, changes in serum sitosterol-to-cholesterol, which reflect those of dietary phytosterol intake and absorption, correlated inversely to LDL-cholesterol changes (r = ?0.256; P = 0.008). In multivariate analyses, baseline LDL-cholesterol, increases in serum sitosterol ratios and statin use were independently associated with LDL-cholesterol reductions.

Conclusions

Small amounts of phytosterols in natural foods appear to be bioactive in cholesterol lowering.