Asian women have greater abdominal and visceral adiposity than Caucasian women with similar body mass index

Background:

In the Multiethnic Cohort Study, Japanese Americans (JA) have lower mean body mass index (BMI) compared with Caucasians, but show a higher waist-to-hip ratio at similar BMI values and a greater risk of diabetes and obesity-associated cancers.

Objective:

We investigated the abdominal, visceral and hepatic fat distribution in these Asian and Caucasian Americans.

Design:

A cross-sectional sample of 60 female cohort participants (30 JA and 30 Caucasians), of ages 60–65 years and BMIs 18.5–40 kg m⁻², underwent anthropometric measurements and a whole-body dual energy X-ray absorptiometry (DXA) scan: a subset of 48 women also had abdominal magnetic resonance imaging (MRI).

Results:

By design, JA women had similar BMIs (mean 26.5 kg m⁻²) to Caucasian women (27.1 kg m⁻²). JA women were found to have a significantly smaller hip circumference (96.9 vs 103.6 cm; P=0.007) but not a significantly lower DXA total fat mass (25.5 vs 28.8 kg; P=0.16). After adjusting for age and DXA total fat mass, JA women had a greater waist-to-hip ratio (0.97 vs 0.89; P<0.0001), DXA trunk fat (15.4 vs 13.9 kg; P=0.0004) and MRI % abdominal visceral fat (23.9 vs 18.5% P=0.01) and a lower DXA leg fat mass (8.2 vs 10.0 kg; P=<.0001). Their MRI % subcutaneous fat (33.4 vs 30.2% P=0.21) and % liver fat (5.8 vs 3.8% P=0.06) did not significantly differ from that of Caucasian women.

Conclusions:

Our findings build on limited past evidence, suggesting that Asian women carry greater abdominal and visceral fat when compared with Caucasian women with similar overall adiposity. This may contribute to their elevated metabolic risk for obesity-related diseases.     

Effect of moderate weight loss on hepatic,pancreatic and visceral lipids in obese subjects

Objective:

To compare the effects of weight loss on visceral and subcutaneous abdominal fat, liver and pancreas lipid content and to test the effects of these changes on metabolic improvement observed after weight loss.

Design:

Weight-loss program designed to achieve a loss of 7–10% of the initial weight.

Subjects:

24 obese subjects (13 males and 11 females) with age ranging from 26 to 69 years and body mass index (BMI) 30.2–50.5 kg m⁻². Measurements: weight, BMI, waist circumference, body composition as assessed by dual-energy X-ray absorptiometry, metabolic variables, leptin, adiponectin, visceral and subcutaneous abdominal fat, liver and pancreas lipid content as assessed by magnetic resonance were evaluated before and after weight loss achieved by hypocaloric diet.

Results:

After a mean body weight decrease of 8.9%, BMI, waist circumference, fat mass, all metabolic variables, homeostasis model assessment of insulin resistance (HOMA), alanine amino transferase, gamma glutamyl transpeptidase, high-sensitivity C-reactive protein (hs-CRP) and leptin, but not adiponectin and high-density lipoprotein-cholesterol, significantly decreased (all P<0.01). Visceral and subcutaneos abdominal fat, liver and pancreas lipid content significantly decreased (all P<0.01). Percent changes in liver lipid content were greater (84.1±3%) than those in lipid pancreas content (42.3±29%) and visceral abdominal fat (31.9±15.6%). After weight loss, percentage of subjects with liver steatosis decreased from 75 to 12.5%. Insulin resistance improvement was predicted by changes in liver lipid content independently of changes in visceral fat, pancreas lipid content, systemic inflammation, leptin and gender.

Conclusion:

Moderate weight loss determines significant decline in visceral abdominal fat, lipid content in liver and pancreas. Reduction of liver lipid content was greater than that of pancreas lipid content and visceral fat loss. Liver lipid content is the strongest predictor of insulin resistance improvement after weight loss.     

Randomized trial of nutrition education added to internet-based information and exercise at the work place for weight loss in a racially diverse population of overweight women

Objective:

Obesity in the United States is highly prevalent, approaching 60% for black women. We investigated whether nutrition education sessions at the work place added to internet-based wellness information and exercise resources would facilitate weight and fat mass loss in a racially diverse population of overweight female employees.

Methods:

A total of 199 (average body mass index 33.9±6.3 kg m⁻²) nondiabetic women (57% black) at our institution were randomized to a 6-month program of either internet-based wellness information (WI) combined with dietitian-led nutrition education group sessions (GS) weekly for 3 months and then monthly with shift in emphasis to weight loss maintenance (n=99) or to WI alone (n=100). All were given access to exercise rooms convenient to their work site. Fat mass was measured by dual-energy X-ray absorptiometry.

Results:

WI+GS subjects lost more weight than WI subjects at 3 months (−2.2±2.8 vs −1.0±3.0 kg, P>0.001). Weight (−2.7±3.9 vs −2.0±3.9 kg) and fat mass (−2.2±3.1 vs −1.7±3.7 kg) loss at 6 months was significant for WI+GS and WI groups (both P<0.001), but without significant difference between groups (both P>0.10); 27% of the WI+GS group achieved ⩾5% loss of initial weight as did 18% of the WI group (P=0.180). Blacks and whites similarly completed the study (67 vs 74%, P=0.303), lost weight (−1.8±3.4 vs −3.3±5.2 kg, P=0.255) and fat mass (−1.6±2.7 vs −2.5±4.3 kg, P=0.532), and achieved ⩾5% loss of initial weight (21 vs 32%, P=0.189), irrespective of group assignment.

Conclusion:

Overweight women provided with internet-based wellness information and exercise resources at the work site lost weight and fat mass, with similar achievement by black and white women. Additional weight loss benefit of nutrition education sessions, apparent at 3 months, was lost by 6 months and may require special emphasis on subjects who fail to achieve weight loss goals to show continued value.     

Comparison of the effects of 52 weeks weight loss with either a high-protein or high-carbohydrate diet on body composition and cardiometabolic risk factors in overweight and obese males

Background:

A high-protein (HP), low-fat weight-loss diet may be advantageous for improving cardiometabolic health outcomes and body composition. To date, only limited research has been conducted in male participants.

Objective:

To evaluate the medium to long-term effects of two, low-fat, hypocaloric diets differing in carbohydrate:protein ratio on body composition and cardiometabolic health outcomes in overweight and obese males.

Design:

One hundred and twenty males (age 50.8±9.3 (s.d.) years, body mass index 33.0±3.9 kg m⁻²) were randomly assigned and consumed a low-fat, isocaloric, energy-restricted diet (7 MJ per day) with either HP (protein:carbohydrate:fat %energy, 35:40:25) or high carbohydrate (HC; 17:58:25). Body weight, body composition and cardiometabolic risk factors were assessed at baseline and after 12 and 52 weeks.

Results:

Sixty-eight participants completed the study (HP, n=33; HC, n=35). At 1 year both the groups experienced similar reductions in body weight (HP, −12.3±8.0 kg (−12%); HC, −10.9±8.6 kg (−11%); P=0.83 time × group interaction) and fat mass (−9.9±6.0 kg (−27%) vs −7.3±5.8 kg (−22%); P=0.11). Participants who consumed the HP diet lost less fat-free mass (−2.6±3.7 kg (−4%) vs −3.8±4.7 kg (−6%); P<0.01). Both groups experienced similar increases in high-density lipoprotein cholesterol (8%) and reductions in total cholesterol (−7%), low-density lipoprotein cholesterol (−9%), triglycerides (−24%), glucose (−3%), insulin (−38%), blood pressure (−7/−12%) and C-reactive protein (−29%), (P⩾0.14).

Conclusion:

In overweight and obese men, both a HP and HC diet reduced body weight and improved cardiometabolic risk factors. Consumption of a HP diet was more effective for improving body composition compared with an HC diet.     

Eating dark and milk chocolate: a randomized crossover study of effects on appetite and energy intake

Objective:

To compare the effect of dark and milk chocolate on appetite sensations and energy intake at an ad libitum test meal in healthy, normal-weight men.

Subjects/methods:

A total of 16 young, healthy, normal-weight men participated in a randomized, crossover study. Test meals were 100 g of either milk (2285 kJ) or dark chocolate (2502 kJ). Visual-analogue scales were used to record appetite sensations before and after the test meal was consumed and subsequently every 30 min for 5 h. An ad libitum meal was served 2 h after the test meal had been consumed.

Results:

The participants felt more satiated, less hungry, and had lower ratings of prospective food consumption after consumption of the dark chocolate than after the milk chocolate. Ratings of the desire to eat something sweet, fatty or savoury were all lower after consumption of the dark chocolate. Energy intake at the ad libitum meal was 17% lower after consumption of the dark chocolate than after the milk chocolate (P=0.002). If the energy provided by the chocolate is included in the calculation, the energy intake after consumption of the dark chocolate was still 8% lower than after the milk chocolate (P=0.01). The dark chocolate load resulted in an overall energy difference of −584 kJ (95% confidence interval (−1027;−141)) during the test period.

Conclusion:

In the present study, dark chocolate promotes satiety, lowers the desire to eat something sweet, and suppresses energy intake compared with milk chocolate.     

Central obesity in males affected by a dyslipidemia-associated genetic polymorphism on APOA1/C3/A4/A5 gene cluster

Background:

Central obesity is a rising epidemic, and often occurs in parallel with dyslipidemia. Furthermore, enhancement of ectopic fat deposition has been observed in both human studies and animal models of altered lipidemic control. Though APOA1/C3/A4/A5 genetic polymorphisms are associated with dyslipidemia, their effect on central obesity is less known.

Method:

The anthropometric and metabolic parameters were taken from obese (body mass index (BMI) ⩾25 kg m⁻²) and non-obese healthy (BMI <25) Taiwanese patients at the initiation weight-loss intervention and 6 months later. The effects of APOA1/C3/A4/A5 genetic polymorphisms were analyzed cross-sectionally and longitudinally. Gender contributions were specifically examined.

Patients:

Three hundred and ninety-eight participants (obese n=262; non-obese healthy n=136) were recruited in total, and 130 obese patients underwent weight-loss treatments.

Results:

APOA5 rs662799 minor allele carriage was associated with unfavorable metabolic profiles in obese but not non-obese individuals at baseline. Further analysis identified gender–genotype interactions in waist-hip ratio (WHR), and that one rs662799 minor allele increased 0.032 WHR unit in obese males as analyzed by linear regression adjusted for age, BMI and plasma triglyceride (TG) (95% confidence interval (CI)=0.014–0.050, P=0.001). The rs662799-associated WHR elevation resulted in increased frequency of central obesity (WHR ⩾1.0) in rs662799 carrying obese males as analyzed by binary logistic regression adjusted for age, BMI and plasma TG (odds ratio=6.52, 95% CI=1.87–22.73, P=0.003). In contrast, APOA5 rs662799 and central obesity were no longer correlated 6 months into weight-loss treatments, owing to significant WHR reductions in male rs662799 minor allele carriers (P=0.001). Meanwhile, hypertriglyceridemia was more prevalent in both male and female obese rs662799 minor allele carriers at baseline (males, P=0.034, females, P=0.007).

Conclusion:

This study highlights the gender-specific and weight-sensitive effects of APOA5 rs662799 on central obesity in Taiwanese individuals, and that these effects are dyslipidemia-independent and weight-loss responsive.     

Water-induced thermogenesis and fat oxidation: a reassessment

Background/Objectives:

Drinking large amounts of water is often recommended for weight control. Whether water intake stimulates energy and fat metabolism is, however, controversial with some studies reporting that drinking half a litre or more of water increases resting energy expenditure (REE) by 10–30% and decreases respiratory quotient (RQ), whereas others report no significant changes in REE or RQ. The aim here was to reassess the concept of water-induced thermogenesis and fat oxidation in humans, with particular focus on interindividual variability in REE and RQ responses, comparison with a time-control Sham drink, and on the potential impact of gender, body composition and abdominal adiposity.

Subjects/Methods:

REE and RQ were measured in healthy young adults (n=27; body mass index range: 18.5–33.9 kg m⁻²), by ventilated hood indirect calorimetry for at least 30 min before and 130 min after ingesting 500 ml of purified (distilled) water at 21–22 °C or after Sham drinking, in a randomized cross-over design. Body composition and abdominal fat were assessed by bioimpedance techniques.

Results:

Drinking 500 ml of distilled water led to marginal increases in REE (<3% above baseline), independently of gender, but which were not significantly different from Sham drinking. RQ was found to fall after the water drink, independently of gender, but it also diminished to a similar extent in response to sham drinking. Interindividual variability in REE and RQ responses was not associated with body fatness, central adiposity or fat-free mass.

Conclusions:

This study conducted in young men and women varying widely in adiposity, comparing the ingestion of distilled water to Sham drinking, suggests that ingestion of purified water per se does not result in the stimulation of thermogenesis or fat oxidation.     

Insulin detemir attenuates food intake,body weight gain and fat mass gain in diet-induced obese Sprague–Dawley rats

Objective:

Initiation and intensification of insulin therapy commonly causes weight gain, a barrier to therapy. A contrasting body of evidence indicates that insulin functions as an adiposity negative feedback signal and reduces food intake, weight gain and adiposity via action in the central nervous system. Basal insulin analogs, detemir (Det) and glargine (Glar), have been associated with less hypoglycemia compared with neutral protamine hagedorn insulin, and Det with less weight gain, especially in patients with higher body mass index (BMI). We sought to determine whether insulin therapy per se causes body weight and fat mass gain when delivered via a clinically relevant subcutaneous (SC) route in the absence of hypoglycemia and glycosuria in non-diabetic lean and diet-induced obese rats.

Materials and methods:

Rats were exposed to either a low-fat diet (LFD; 13.5% fat) or high-fat diet (HFD; 60% fat), and received Det (0.5 U kg⁻¹), Glar (0.2 U kg⁻¹) or vehicle (Veh) SC once daily for 4 weeks. These dosages of insulin were equipotent in rats with respect to blood–glucose concentration and did not induce hypoglycemia.

Results:

As predicted by current models of energy homeostasis, neither insulin Det nor Glar therapy affected food intake and weight gain in LFD rats. Det treatment significantly attenuated food intake, body weight gain and fat mass gain relative to the Glar and Veh in high-fat fed animals, mirroring observations in humans.

Conclusions:

That neither insulin group gained excess weight, suggests weight gain with SC basal insulin therapy may not be inevitable. Our data further suggest that Det possesses a unique property to attenuate the development of obesity associated with a HFD.     

A comparison of effects of lard and hydrogenated vegetable shortening on the development of high-fat diet-induced obesity in rats

Background:

Obesity is associated with increased consumption and preference for dietary fat. Experimental models of fat-induced obesity use either lard or vegetable shortening. Yet, there are no direct comparisons of these commonly used fat sources, or the influence of their fatty acid composition, on the development of diet-induced obesity.

Objective:

To compare the effects of lard and hydrogenated vegetable-shortening diets, which differ in their fatty acid composition, on weight gain and the development of obesity and insulin resistance in rats.

Methods and design:

Male Wistar rats were fed ad libitum for 14 weeks high-fat diets containing either (1) high vegetable fat (HVF, 60 kcal% from vegetable shortening) or (2) high lard fat (HLF, 60 kcal% from lard). Rats fed normal-fat (NF, 16 kcal% from vegetable shortening) diet served as control. Body weight, food intake, adipose tissue mass, serum 25[OH]D₃, glucose, insulin and fatty acid composition of diets were measured.

Results:

Rats fed either of the two high-fat diets had higher energy intake, weight gain and fat accretion than rats fed normal-fat diet. However, rats fed the HLF diet consumed more calories and gained more weight and body fat with greater increases of 32% in total (158.5±8.2 vs 120.2±6.6 g, P<0.05), 30% in visceral (104.4±5.2 vs 80.3±4.2 g, P<0.05) and 36% in subcutaneous fat mass (54.1±3.6 vs 39.9±3.1 g, P<0.05), compared with rats fed the HVF diet. Higher visceral adiposity was positively correlated with serum insulin (r=0.376, P<0.05) and homeostatic model assessment insulin resistance (r=0.391, P<0.05).

Conclusion:

We conclude that lard-based high-fat diets accentuate the increase in weight gain and the development of obesity and insulin resistance more than hydrogenated vegetable-shortening diets. These results further point to the importance of standardizing fatty acid composition and type of fat used in determining outcomes of consuming high-fat diets.     

Can a relatively low-intensity intervention by health professionals prevent weight gain in mid-age women? 12-Month outcomes of the 40-Something randomised controlled trial

Background:

Weight gain in perimenopausal women results in increased visceral adipose tissue, leading to metabolic syndrome and associated comorbidities. Despite a high prevalence of weight gain at this life stage, interventions to prevent menopausal obesity are lacking.

Aim:

To test the effectiveness of an intervention delivered by health professionals using a motivational interviewing (MI) counselling style in preventing weight gain in non-obese (body mass index (BMI) 18.5 and 29.9 kg m⁻²) women in late premenopause.

Methods:

In a randomised controlled trial, 54 women (mean (s.d.) age 47.3 (1.8) years; BMI 25.1 (2.4) kg m⁻²) who had menstruated within the preceding 3 months were randomly assigned to an MI intervention (n=28) (five health professional MI counselling sessions) or a self-directed intervention (SDI) (print materials only) (n=26). The primary outcome, body weight (kg) and secondary outcomes (blood lipids, glucose, body fat %, lean mass % and waist circumference) were measured at baseline and postintervention (12 months), and intention-to-treat analysis was conducted.

Results:

Forty women completed all measures and adhered to all protocols. The weight at 12 months for the MI group of 65.6 kg (95% CI: 64.5; 66.8) was significantly different (P=0.034) from the SDI group of 67.4 kg (95% CI: 66.2; 68.6). When stratified by baseline BMI category, the MI group lost significantly more weight (−2.6 kg; 95% CI: −3.9; −1.2) than the SDI group (−0.1 kg; 95% CI: −1.2; 1.0, P=0.002) for the healthy weight women. The overweight women lost weight regardless of the intervention group, with no between-group difference (−3.5 kg; 95% CI: −6.1, −1.0 and −2.3; 95% CI: −4.1, −0.5, P=0.467).

Conclusion:

This relatively low-intensity intervention, incorporating MI into health professional counselling, not only effectively prevented weight gain but also achieved significant weight loss and decreased diastolic blood pressure. Further refinements are required to optimise outcomes for overweight women.     

Measures of body fat in South Asian adults

Background:

South Asian people who originate from the Indian subcontinent have greater percent body fat (%BF) for the same body mass index (BMI) compared with white Caucasians. This has been implicated in their increased risk of type 2 diabetes and cardiovascular disease. There is limited information comparing different measures of body fat in this ethnic group.

Objectives:

The objectives of this study were: (1) to investigate the correlation of %BF measured by a foot-to-foot bioelectrical impedance analysis (FF-BIA) against the BOD POD, a method of air-displacement plethysmography, and (2) to determine the correlations of simple anthropometric measures, (that is, BMI, body adiposity index (BAI), waist circumference (WC), hip circumference (HC) and waist-to-hip ratio (WHR)) against the BOD POD measure of body fat.

Methods:

Eighty apparently healthy South Asian men and women were recruited from the community, and measurements of height, weight, WC, HC and body composition using Tanita FF-BIA and BOD POD were taken.

Results:

The mean±s.d. age of participants was 27.78±10.49 years, 42.5% were women, and the mean BMI was 22.68±3.51 kg m⁻². The mean body fat (%BF) calculated by FF-BIA and BOD POD was 21.94±7.88% and 26.20±8.47%, respectively. The %BF calculated by FF-BIA was highly correlated with the BOD POD (Pearson''s r=0.83, P<0.001), however, FF-BIA underestimated %BF by 4.3%. When anthropometric measures were compared with % BF by BOD POD, the BAI showed the strongest correlation (r=0.74) and the WHR showed the weakest (r=0.33). BAI generally underestimated %BF by 2.6% in comparison with %BF by BOD POD. The correlations of BOD POD with other measures of %BF were much stronger in subjects with a BMI >21 kg m⁻² than those with a BMI ⩽21 kg m⁻².

Conclusion:

The FF-BIA and BAI estimates of %BF are highly correlated with that of BOD POD among people of South Asian origin, although both methods somewhat underestimate % BF. Furthermore, their correlations with % BF from BOD POD are significantly weakened among men and women with a BMI ⩽21 kg m⁻².     

Effect of phosphorus supplementation on weight gain and waist circumference of overweight/obese adults: a randomized clinical trial

Background:

Phosphorus status is inversely correlated with body weight; however, the effect of phosphorus supplementation on body weight in a controlled design has not been studied.

Methods:

This is a double-blind, randomized, placebo-controlled trial of 63 adults aged 18–45 years with a body mass index (BMI) of ⩾25 kg m⁻² and normal kidney function at the American University of Beirut. Participants were randomly assigned to the placebo or phosphorus group where daily placebo or phosphorus supplements were ingested with three main meals (breakfast, lunch and dinner) for a period of 12 weeks. Primary outcomes were changes in anthropometric measures, blood metabolites (including lipid profile, glucose and insulin) and subjective appetite scores. The trial is registered with Clinical Trial.gov, {"type":"clinical-trial","attrs":{"text":"NCT02329990","term_id":"NCT02329990"}}NCT02329990.

Results:

Body weight was significantly lower in the phosphorus group when compared with the placebo group (−0.65 kg (95% confidence interval (CI) −1.69 to 0.40) vs 1.13 kg (95% CI 0.19 to 2.06), P=0.01). Similarly, BMI and waist circumference were significantly lower in the phosphorus group when compared with the placebo group (−0.24 kg m⁻² (95% CI −0.59 to 0.12) vs 0.42 kg m⁻² (95% CI 0.05 to 0.78), P=0.01; −3.62 cm (95% CI−4.90 to −2.33) vs 0.38 cm ( 95% CI−0.44 to 1.20), P<0.001; respectively). Several parameters of subjective appetite scores were decreased in the phosphorus-supplemented group.

Conclusions:

Phosphorus supplementation for 12 weeks significantly decreases body weight, BMI, waist circumference and subjective appetite scores. These findings support a promising role of the mineral phosphorus in the prevention and management of obesity, especially abdominal adiposity. The exact mechanisms of action and longer-term effects still need to be elucidated.     

Circulating sCD36 is associated with unhealthy fat distribution and elevated circulating triglycerides in morbidly obese individuals

Background:

The recently identified circulating sCD36 has been proposed to reflect tissue CD36 expression, and is upregulated in case of obesity, insulin resistance and hepatic steatosis. The aim of this study was to explore the effect of weight loss secondary to bariatric surgery in relation to sCD36 among morbidly obese individuals. Furthermore, we investigated the levels of sCD36 in relation to obesity-related metabolic complications, low-grade inflammation and fat distribution.

Methods:

Twenty morbidly obese individuals (body mass index (BMI) 43.0±5.4 kg m⁻²) with a referral to Roux-en-Y gastric bypass were included. Anthropometric measurements and fasting blood samples were collected at a preoperative baseline visit and 3 months after surgery. sCD36 was measured by an in-house assay, whereas insulin sensitivity and the hepatic fat accumulation were estimated by the homeostasis model assessment (HOMA-%S) and liver fat percentage (LF%), respectively.

Results:

Postoperatively, BMI was reduced by 20% to 34.3±5.2 kg m⁻² (P<0.001). sCD36 was reduced by 31% (P=0.001) and improvements were observed in the amount of fat mass (P<0.001), truncal fat mass (P<0.001), circulating triglycerides (P=0.001), HOMA-%S (P=0.007), LF% (P=0.001) and the inflammatory marker high-sensitive C-reactive protein (P=0.005). sCD36 correlated with triglycerides (ρ=0.523, P=0.001) and truncal fat mass (ρ=0.357, P=0.026), and triglycerides were found to be an independent predictor of sCD36. At baseline, participants with the metabolic syndrome had a higher LF% and higher levels of the inflammatory biomarker YKL-40 (P=0.003 and P=0.014) as well as a tendency towards higher levels of sCD36.

Conclusion:

sCD36 was reduced by weight loss and associated with an unhealthy fat accumulation and circulating triglycerides, which support the proposed role of sCD36 as a biochemical marker of obesity-related metabolic complications and risks.     

Plasma choline metabolites associate with metabolic stress among young overweight men in a genotype-specific manner

OBJECTIVES:

We aimed to test the hypotheses that (i) plasma choline metabolites differ between normal (body mass index (BMI)<25 kg m⁻²) and overweight (BMI ⩾25 kg m⁻²) men, and (ii) an elevated BMI alters associations between plasma choline metabolites and indicators of metabolic stress.

DESIGN:

This was a cross-sectional study. A one-time fasting blood sample was obtained for measurements of the choline metabolites and metabolic stress indicators (that is, serum alanine aminotransferase (ALT), glucose, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides and homocysteine), and for genotype determination.

SUBJECTS:

The analysis was conducted with 237 Mexican American men with a median age of 22 years.

RESULTS:

Compared with men with a normal BMI (n=98), those with an elevated BMI (n=139) had 6% lower (P=0.049) plasma betaine and an 11% lower (P=0.002) plasma betaine to choline ratio. Among men with an elevated BMI, plasma betaine and the plasma betaine to choline ratio positively associated (P⩽0.044) with a favorable serum cholesterol profile, and inversely associated (P=0.001) with serum ALT, a marker of liver dysfunction. The phosphatidylethanolamine N-methyltransferase (PEMT) 5465G→A (rs7946) genotype interacted (P⩽0.007) with the plasma betaine to choline ratio to modulate indicators of metabolic stress with stronger inverse associations observed among overweight men with the PEMT 5465GG genotype.

CONCLUSIONS:

Plasma choline metabolites predict metabolic stress among overweight men often in a genotype-specific manner. The diminished betaine among overweight men coupled with the inverse association between betaine and metabolic stress suggest that betaine supplementation may be effective in mitigating some of the metabolic insults arising from lipid overload.     

Serum S-adenosylmethionine,but not methionine,increases in response to overfeeding in humans

Background:

Plasma concentration of the methyl donor S-adenosylmethionine (SAM) is linearly associated with body mass index (BMI) and fat mass. As SAM is a high-energy compound and a sensor of cellular nutrient status, we hypothesized that SAM would increase with overfeeding.

Methods:

Forty normal to overweight men and women were overfed by 1250 kcal per day for 28 days.

Results:

Serum SAM increased from 106 to 130 nmol/l (P=0.006). In stratified analysis, only those with weight gain above the median (high-weight gainers; average weight gain 3.9±0.3 kg) had increased SAM (+42%, P=0.001), whereas low-weight gainers (weight gain 1.5±0.2 kg) did not (P_interaction=0.018). Overfeeding did not alter serum concentrations of the SAM precursor, methionine or the products, S-adenosyl-homocysteine and homocysteine. The SAM/SAH (S-adenosylhomocysteine) ratio was unchanged in the total population, but increased in high-weight gainers (+52%, P=0.006, P_interaction =0.005). Change in SAM correlated positively with change in weight (r=0.33, P=0.041) and fat mass (r=0.44, P=0.009), but not with change in protein intake or plasma methionine, glucose, insulin or low-density lipoprotein (LDL)-cholesterol.

Conclusion:

Overfeeding raised serum SAM in proportion to the fat mass gained. The increase in SAM may help stabilize methionine levels, and denotes a responsiveness of SAM to nutrient state in humans. The role of SAM in human energy metabolism deserves further attention.     

Reproducibility of ultrasonography for assessing abdominal fat distribution in a population at high risk of diabetes

Background:

Visceral fat plays an important role in the development of metabolic disease independently of the effect of overall abdominal fat. Ultrasonography is an accessible method of accurately assessing abdominal fat distribution in epidemiological studies, but few details about the reproducibility of this method have been published.

Objective:

The aim of this study was to investigate the reproducibility of ultrasonography in the assessment of abdominal fat distribution in a population at high risk of type 2 diabetes.

Design and Methods:

Ultrasonography was used to estimate visceral and subcutaneous abdominal fat. Intra- and interobserver variation, short-term variation and variation between estimates in the fasting and non-fasting state were examined in three samples of 30, 33 and 23 participants from the ADDITION-PRO study. A variance components model was used to calculate intra- and interobserver variation, and Bland–Altman plots were drawn for all three substudies.

Results:

Coefficients of variation for intra- and interobserver variation were in the range 3.4–6.1%, except for interobserver variation for subcutaneous fat (9.5%). Short-term variation over a median of 35 days had a coefficient of variation of 15%. The effect of a meal was primarily on the visceral estimates and did not extend beyond the first postprandial hour. Non-fasting visceral estimates were larger than fasting estimates.

Conclusion:

Both visceral and subcutaneous fat can be estimated with ultrasonography with adequate intra- and interobserver reproducibility by clinical researchers with limited training, making it a feasible method of assessing abdominal fat distribution in epidemiological studies.     

The cannabinoid Δ9-tetrahydrocannabivarin (THCV) ameliorates insulin sensitivity in two mouse models of obesity

Background:

Cannabinoid type-1 (CB1) receptor inverse agonists improve type 2 diabetes and dyslipidaemia but were discontinued due to adverse psychiatric effects. Δ⁹-Tetrahydrocannabivarin (THCV) is a neutral CB1 antagonist producing hypophagia and body weight reduction in lean mice. We investigated its effects in dietary-induced (DIO) and genetically (ob/ob) obese mice.

Methods:

We performed two dose-ranging studies in DIO mice; study 1: 0.3, 1, 2.5, 5 and 12.5 mg kg⁻¹, oral twice daily for 30 days and study 2: 0.1, 0.5, 2.5 and 12.5 mg kg⁻¹, oral, once daily for 45 days. One pilot (study 3: 0.3 and 3 mg kg⁻¹, oral, once daily) and one full dose-ranging (study 4: 0.1, 0.5, 2.5 and 12.5 mg kg⁻¹, oral, once daily) studies in ob/ob mice for 30 days. The CB1 inverse agonist, AM251, oral, 10 mg kg⁻¹ once daily or 5 mg kg⁻¹ twice daily was used as the positive control. Cumulative food and water intake, body weight gain, energy expenditure, glucose and insulin levels (fasting or during oral glucose tolerance tests), plasma high-density lipoprotein and total cholesterol, and liver triglycerides were measured. HL-5 hepatocytes or C₂C₁₂ myotubes made insulin-resistant with chronic insulin or palmitic acid were treated with 0, 1, 3 and 10 μℳ THCV or AM251.

Results:

THCV did not significantly affect food intake or body weight gain in any of the studies, but produced an early and transient increase in energy expenditure. It dose-dependently reduced glucose intolerance in ob/ob mice and improved glucose tolerance and increased insulin sensitivity in DIO mice, without consistently affecting plasma lipids. THCV also restored insulin signalling in insulin-resistant hepatocytes and myotubes.

Conclusions:

THCV is a new potential treatment against obesity-associated glucose intolerance with pharmacology different from that of CB1 inverse agonists/antagonists.     

Abdominal adiposity and daily step counts as determinants of glycemic control in a cohort of patients with type 2 diabetes mellitus

Objective:

Favorable effects of walking levels on glycemic control have been hypothesized to be mediated through reductions in abdominal adiposity, but this has not been well studied. We addressed this issue in patients treated for type 2 diabetes.

Design:

Cross-sectional analysis.

Subjects:

A total of 201 subjects with type 2 diabetes underwent assessments of pedometer-measured daily step counts, blood pressure, A1C and anthropometric measures (2006–2010). Associations of anthropometric indicators of abdominal adiposity (that is, waist circumference; waist-to-hip ratio (WHR)) with A1C were evaluated through linear regression models adjusting for age, ethnicity, sex and the use of insulin and oral hypoglycemic agents. Models including waist circumference were additionally adjusted for body mass index (BMI). A similar approach was used to examine A1C and daily step associations.

Results:

Among the 190 subjects (mean age 60 years; mean BMI 30.4 kg m⁻²), mean values (s.d.) for waist circumference and WHR were respectively, 99.1 cm (13.3) and 0.88 (0.07) in women, and 104.5 cm (13.1) and 0.97 (0.06) in men. Mean A1C and daily step count were respectively, 7.6% (1.4) and 5 338 steps per day (2609), and were similar for both sexes.There was a 0.51% (95% confidence interval (CI): 0.10, 0.93) A1C increment per s.d. increase in waist circumference and a 0.32% (95% CI: 0.08, 0.56) A1C increment per s.d. increase in WHR in fully adjusted models. Each s.d. increase in daily step count was associated with clinically significant reductions in waist circumference and BMI. Each s.d. increase in daily steps was associated with a 0.21% (95% CI: 0.02, 0.41) A1C decrement that declined to 0.16% (95% CI: −0.35, 0.04) with further adjustment for anthropometric indicators of abdominal adiposity.

Conclusion:

Higher daily steps may be associated with lower A1C values both directly and via changes in abdominal adiposity.     

A randomized comparison of a commercially available portion-controlled weight-loss intervention with a diabetes self-management education program

Objective:

This study examined the efficacy of a commercially available, portion-controlled diet (PCD) on body weight and HbA_1c over 6 months in obese patients with type 2 diabetes.

Research Design and Methods:

One-hundred participants with a mean±s.d. age of 55.6±10.6 year, body weight of 102.9±18.4 kg and HbA_1c of 7.7±1.3% were randomly assigned to a 9-session group lifestyle intervention that included a PCD or to a 9-session group program of diabetes self-management education (DSME). Participants in the two groups were prescribed the same goals for energy intake (1250–1550 kcal per day) and physical activity (200 min per week).

Results:

While both groups produced significant improvements in weight and HbA_1c after 6 months of treatment, PCD participants lost 7.3 kg [95% confidence interval (CI): −5.8 to −8.8 kg], compared with 2.2 kg (95% CI: −0.7 to −3.7 kg) in the DSME group (P<0.0001). Significantly more PCD than DSME participants lost ⩾5% of initial weight (54.0% vs 14.0%, P<0.0001) and ⩾10% (26.0% vs 6.0%, P<0.0001). HbA_1c declined by 0.7% (95% CI: −0.4 to −1.0%) in the PCD group, compared with 0.4% (95% CI: −0.1 to −0.7%) in DSME (P<0.026). Across both groups, larger weight losses were associated with greater reductions in HbA_1c (r=0.52, P<0.0001).

Conclusions:

These findings demonstrate that a commercially available portion-controlled meal plan can induce clinically meaningful improvements in weight and glycemic control in obese individuals with type 2 diabetes. These data have implications for the management of obesity in primary care, as now provided by the Centers for Medicare and Medicaid Services.