Evaluation of the Association between Arsenic and Diabetes: A National Toxicology Program Workshop Review

Background: Diabetes affects an estimated 346 million persons globally, and total deaths from diabetes are projected to increase > 50% in the next decade. Understanding the role of environmental chemicals in the development or progression of diabetes is an emerging issue in environmental health. In 2011, the National Toxicology Program (NTP) organized a workshop to assess the literature for evidence of associations between certain chemicals, including inorganic arsenic, and diabetes and/or obesity to help develop a focused research agenda. This review is derived from discussions at that workshop.Objectives: Our objectives were to assess the consistency, strength/weaknesses, and biological plausibility of findings in the scientific literature regarding arsenic and diabetes and to identify data gaps and areas for future evaluation or research. The extent of the existing literature was insufficient to consider obesity as an outcome.Data Sources, Extraction, and Synthesis: Studies related to arsenic and diabetes or obesity were identified through PubMed and supplemented with relevant studies identified by reviewing the reference lists in the primary literature or review articles.Conclusions: Existing human data provide limited to sufficient support for an association between arsenic and diabetes in populations with relatively high exposure levels (≥ 150 µg arsenic/L in drinking water). The evidence is insufficient to conclude that arsenic is associated with diabetes in lower exposure (< 150 µg arsenic/L drinking water), although recent studies with better measures of outcome and exposure support an association. The animal literature as a whole was inconclusive; however, studies using better measures of diabetes-relevant end points support a link between arsenic and diabetes.     

Impact of case ascertainment on recent trends in diabetes incidence in Rochester, Minnesota

The authors previously reported an increase in the incidence of diabetes mellitus among Rochester, Minnesota, residents during the period 1970-1989. This study provides updated rates from data collected through 1994. Trends in diabetes surveillance, i.e., the proportion of residents who had a blood glucose measurement in each year between 1987 and 1994, are also provided. The authors reviewed medical records to identify residents aged 30 years or more who first met National Diabetes Data Group criteria for diabetes between January 1, 1970, and December 31, 1994. Age- and sex-adjusted incidence rates were calculated for successive quinquennia (5-year periods), and Poisson regression was used to test for an effect of calendar year; calendar period (1970-1989 vs. 1990-1994) was added to assess whether the association with calendar year varied in the most recent quinquennium. Altogether, 1,992 Rochester residents first met National Diabetes Data Group criteria for diabetes between 1970 and 1994. The age-adjusted incidence per 100,000 person-years increased 67% for males (267.0 vs. 444.8) and 42% for females (225.4 vs. 319.1) between 1970-1974 and 1990-1994. Calendar year (p < 0.001) and calendar period (p = 0.026) were significant, suggesting that rates accelerated during 1990-1994. The proportion of residents with at least one blood glucose measurement per year was unchanged (p = 0.181) from 1987 to 1994, while the incidence of diabetes increased (p = 0.033). Thus, the authors conclude that the increase in diabetes incidence accelerated over the last quinquennium and was not due to increased surveillance.     

Stillbirth in rural Bangladesh: arsenic exposure and other etiological factors: a report from Gonoshasthaya Kendra

Objective

To use data collected by Gonoshasthaya Kendra, a large nongovernmental organization providing health care to some 600 villages, to describe the epidemiological pattern of stillbirth and any additional contribution made by arsenic contamination of hand-pump wells in Bangladesh.

Methods

Completed pregnancies and outcomes (n = 30 984) for two calendar years, together with existing data on 26 socioeconomic and health factors were selected for study. The health care in these villages was administered from 16 geographical centres; information on the average arsenic concentration in each centre was obtained from the National Hydrochemical Survey. After univariate analysis, a multivariate, multilevel, logistic model for stillbirth was developed. The additional effect of arsenic was calculated having adjusted for all potential confounders thus identified.

Findings

The overall stillbirth rate was 3.4% (1056/30 984) and increased with estimated arsenic concentration (2.96% at < 10 µg/l; 3.79% at 10 µg/l to < 50 µg/l; 4.43% at ≥ 50 µg/l). Having adjusted for 17 socioeconomic and health factors, the odds ratios estimated for arsenic (with < 10 µg/l as reference) remained raised: 1.23 (95% confidence interval, CI: 0.87–1.74) at 10 µg/l to < 50 µg/l and 1.80 (95% CI: 1.14–2.86) at 50 µg/l or greater.

Conclusion

An increased risk of stillbirth is associated with arsenic contamination. This risk, substantial enough to be detected by an ecological approach and not readily attributable to unmeasured confounding, is essentially preventable and all efforts must be made to protect women at high risk.     

Childhood Lead Poisoning Associated with Gold Ore Processing: a Village-Level Investigation��Zamfara State, Nigeria, October�CNovember 2010

Background: During May–June 2010, a childhood lead poisoning outbreak related to gold ore processing was confirmed in two villages in Zamfara State, Nigeria. During June–September of that year, villages with suspected or confirmed childhood lead poisoning continued to be identified in Zamfara State.Objectives: We investigated the extent of childhood lead poisoning [≥ 1 child with a blood lead level (BLL) ≥ 10 µg/dL] and lead contamination (≥ 1 soil/dust sample with a lead level > 400 parts per million) among villages in Zamfara State and identified villages that should be prioritized for urgent interventions.Methods: We used chain-referral sampling to identify villages of interest, defined as villages suspected of participation in gold ore processing during the previous 12 months. We interviewed villagers, determined BLLs among children < 5 years of age, and analyzed soil/dust from public areas and homes for lead.Results: We identified 131 villages of interest and visited 74 (56%) villages in three local government areas. Fifty-four (77%) of 70 villages that completed the survey reported gold ore processing. Ore-processing villages were more likely to have ≥ 1 child < 5 years of age with lead poisoning (68% vs. 50%, p = 0.17) or death following convulsions (74% vs. 44%, p = 0.02). Soil/dust contamination and BLL ≥ 45 µg/dL were identified in ore-processing villages only [50% (p < 0.001) and 15% (p = 0.22), respectively]. The odds of childhood lead poisoning or lead contamination was 3.5 times as high in ore-processing villages than the other villages (95% confidence interval: 1.1, 11.3).Conclusion: Childhood lead poisoning and lead contamination were widespread in surveyed areas, particularly among villages that had processed ore recently. Urgent interventions are required to reduce lead exposure, morbidity, and mortality in affected communities.     

Coconut-derived D-xylose affects postprandial glucose and insulin responses in healthy individuals

Metabolic alterations including postprandial hyperglycemia have been implicated in the development of obesity-related diseases. Xylose is a sucrase inhibitor suggested to suppress the postprandial glucose surge. The objectives of this study were to assess the inhibitory effects of two different concentrations of xylose on postprandial glucose and insulin responses and to evaluate its efficacy in the presence of other macronutrients. Randomized double-blind cross-over studies were conducted to examine the effect of D-xylose on postprandial glucose and insulin response following the oral glucose tolerance test (OGTT). In study 1, the overnight-fasted study subjects (n = 49) consumed a test sucrose solution (50 g sucrose in 130 ml water) containing 0, 5, or 7.5 g D-xylose powder. In study 2, the overnight-fasted study subjects (n = 50) consumed a test meal (50 g sucrose in a 60 g muffin and 200 ml sucrose-containing solution). The control meal provided 64.5 g of carbohydrates, 4.5 g of fat, and 10 g of protein. The xylose meal was identical to the control meal except 5 g of xylose was added to the muffin mix. In study 1, the 5 g xylose-containing solutions exhibited significantly lower area under the glucose curve (AUCg) and area under the insulin curve (AUCi) values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P < 0.0001), 0-60 min (P < 0.0001, P < 0.0001), 0-90 min (P < 0.0001, P < 0.0001) and 0-120 min (P = 0.0071, P = 0.0016). In study 2, the test meal exhibited significantly lower AUCg and AUCi values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P = 0.0005), 0-60 min (P = 0.0002, P = 0.0025), and 0-90 min (P = 0.0396, P = 0.0246). In conclusion, xylose showed an acute suppressive effect on the postprandial glucose and insulin surges.     

Decline in incidence of epidemic glucose intolerance in Nauruans: implications for the "thrifty genotype"

Trends in the prevalence and incidence of non-insulin-dependent diabetes mellitus and impaired glucose tolerance were studied in Micronesian Nauruans aged 20 years and above, by linking glucose tolerance data collected during population surveys performed in 1975/1976, 1982, and 1987. Based on World Health Organization criteria, the age-standardized prevalence of non-insulin-dependent diabetes mellitus has remained relatively constant (24.0% in 1987), but the prevalence of impaired glucose tolerance has decreased significantly from 21.1% (95% confidence interval (CI) 17.0-25.3) in 1975/1976 to 8.7% (95% CI 7.1-10.3) in 1987. Between the periods 1975/1976-1982 and 1982-1987, the incidence of progression from normal glucose tolerance to either impaired glucose tolerance (incidence rate ratio (IRR) = 0.55, p less than 0.01) or non-insulin-dependent diabetes (IRR = 0.46, p less than 0.05) has decreased dramatically, while progression from impaired glucose tolerance to non-insulin-dependent diabetes has increased (IRR = 1.23). The overall age-standardized incidence of non-insulin-dependent diabetes has declined from 26.2 cases/1,000 person-years in 1975/1976-1982 to 22.5 cases/1,000 person-years in 1982-1987. As there were no changes in the frequency of recognized risk factors, the decline in incidence of glucose intolerance is probably due to the intensity of the epidemic in Nauru, which has already removed a high proportion of the genetically susceptible individuals from the pool with normal glucose tolerance. Coupled with the observations that mortality is higher and fertility lower in diabetic Nauruans across the age range, the observed decline in the incidence and prevalence of non-insulin-dependent diabetes mellitus and impaired glucose tolerance may presage a fall in the population frequency of the diabetic genotype, at least in its more severe form, as might be predicted on the basis of Neel's "thrifty genotype" hypothesis.     

Polychlorinated biphenyl (PCB) exposure and diabetes: results from the Anniston Community Health Survey

Background: Polychlorinated biphenyls (PCBs) manufactured in Anniston, Alabama, from 1929 to 1971 caused significant environmental contamination. The Anniston population remains one of the most highly exposed in the world.Objectives: Reports of increased diabetes in PCB-exposed populations led us to examine possible associations in Anniston residents.Methods: Volunteers (n = 774) from a cross-sectional study of randomly selected households and adults who completed the Anniston Community Health Survey also underwent measurements of height, weight, fasting glucose, lipid, and PCB congener levels and verification of medications. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationships between PCBs and diabetes, adjusting for diabetes risk factors. Participants with prediabetes were excluded from the logistic regression analyses.Results: Participants were 47% African American, 70% female, with a mean age of 54.8 years. The prevalence of diabetes was 27% in the study population, corresponding to an estimated prevalence of 16% for Anniston overall; the PCB body burden of 35 major congeners ranged from 0.11 to 170.42 ppb, wet weight. The adjusted OR comparing the prevalence of diabetes in the fifth versus first quintile of serum PCB was 2.78 (95% CI: 1.00, 7.73), with similar associations estimated for second through fourth quintiles. In participants < 55 years of age, the adjusted OR for diabetes for the highest versus lowest quintile was 4.78 (95% CI: 1.11, 20.6), whereas in those ≥ 55 years of age, we observed no significant associations with PCBs. Elevated diabetes prevalence was observed with a 1 SD increase in log PCB levels in women (OR = 1.52; 95% CI: 1.01, 2.28); a decreased prevalence was observed in men (OR = 0.68; 95% CI: 0.33, 1.41).Conclusions: We observed significant associations between elevated PCB levels and diabetes mostly due to associations in women and in individuals < 55 years of age.     

Risk of urinary tract infection and asymptomatic bacteriuria among diabetic and nondiabetic postmenopausal women

No prospective data exist on the risk of microbiologically confirmed urinary tract infection (UTI) and asymptomatic bacteriuria (AB) in relation to diabetes mellitus and its characteristics. The authors prospectively (1998-2002) followed 218 diabetic and 799 nondiabetic Washington State women aged 55-75 years for UTI and AB. The baseline examination and two annual follow-up examinations included urine culture, measurement of hemoglobin A1c and postvoid residual bladder volume, and a survey of diabetes and other characteristics. Surveillance for UTI included self-reports confirmed by microbiologic culture and medical record review. UTI incidence per 100 person-years was 12.2 for diabetic women and 6.7 for nondiabetic women (relative risk (RR) = 1.8, 95% confidence interval (CI): 1.2, 2.7). AB incidence per 100 person-years was 6.7 for diabetic women and 3.0 for nondiabetic women (RR = 2.3, 95% CI: 1.3, 3.9). In Cox models adjusted for multiple covariates, the increased UTI risk occurred mainly in women taking insulin (RR = 3.7, 95% CI: 1.8, 7.3) and women with a longer diabetes duration (> or =10 years; RR = 2.6, 95% CI: 1.3, 5.1) compared with nondiabetic women. No clear linear trend between hemoglobin A1c and UTI or AB risk was seen. Postmenopausal women with diabetes have higher risks of UTI and AB in relation to diabetes duration and severity but not to recent glucose control.     

Five-year incidence of type 2 diabetes mellitus among cardiovascular disease-free Greek adults: findings from the ATTICA study

Objective

We evaluated the 5-year incidence of diabetes in an adult population from Greece.

Research design and methods

3042 individuals (>18 years), free of cardiovascular disease, participated in the baseline examination (during 2001–2002). Of this sample, 1012 men and 1035 women were found alive at the time of follow-up, while 32 (2.1%) men and 22 (1.4%) women died during this period. The rest were lost to follow-up. Incidence of type 2 diabetes mellitus was evaluated in 1806 participants who did not have diabetes at baseline.

Results

The age-adjusted 5-year incidence of diabetes was 5.5% (men, 5.8%; women, 5.2%). A linear trend was observed between diabetes incidence and age (5.6% increases in incidence per 1-year difference in age, p < 0.001). Multiple logistic regression analysis revealed that age (OR per 1 yr = 1.04, 95% CI 1.02–1.06), waist (OR per 1 cm = 1.02, 95% CI 1.01–1.003), physical activity (OR = 0.62, 95% CI 0.35–1.02) and family history of diabetes (OR = 2.65, 95% CI 1.58–4.53), as well as fasting glucose levels (OR per 1 mg/dl = 1.05, 95% CI 1.03–1.07), were the most significant baseline predictors for diabetes, after adjusting for various potential confounders. Additionally, presence of metabolic syndrome at baseline evaluation 2.95-fold the risk of diabetes (95% CI 1.89–4.61), and showed better classification ability than the model that contained the components of the syndrome (ie, correct classification rate: 94.5% vs. 92.3%).

Conclusion

Our findings show that a 5.5% incidence rate of diabetes within a 5-year period, which suggests that the prevalence of this disorder in Greece is rising. Aging, heredity, and metabolic syndrome were the most significant determinants of diabetes.     

Relations between exposure to arsenic, skin lesions, and glucosuria

OBJECTIVES: Exposure to arsenic causes keratosis, hyperpigmentation, and hypopigmentation and seemingly also diabetes mellitus, at least in subjects with skin lesions. Here we evaluate the relations of arsenical skin lesions and glucosuria as a proxy for diabetes mellitus. METHODS: Through existing measurements of arsenic in drinking water in Bangladesh, wells with and without arsenic contamination were identified. Based on a questionnaire, 1595 subjects > or = 30 years of age were interviewed; 1481 had a history of drinking water contaminated with arsenic whereas 114 had not. Time weighted mean arsenic concentrations and mg-years/l of exposure to arsenic were estimated based on the history of consumption of well water and current arsenic concentrations. Urine samples from the study subjects were tested by means of a glucometric strip. People with positive tests were considered to be cases of glucosuria. RESULTS: A total of 430 (29%) of the exposed people were found to have skin lesions. Corresponding to drinking water with < 0.5, 0.5-1.0, and > 1.0 mg/l of arsenic, and with the 114 unexposed subjects as the reference, the prevalence ratios for glucosuria, as adjusted for age and sex, were 0.8, 1.4, and 1.4 for those without skin lesions, and 1.1, 2.2, and 2.6 for those with skin lesions. Taking exposure as < 1.0, 1.0-5.0, > 5.0-10.0 and > 10.0 mg- years/l of exposure to arsenic the prevalence ratios, similarly adjusted, were 0.4, 0.9, 1.2, and 1.7 for those without and 0.8, 1.7, 2.1, and 2.9 for those with skin lesions. All series of risk estimates were significant for trend, (p < 0.01). CONCLUSIONS: The results suggest that skin lesions and diabetes mellitus, as here indicated by glucosuria, are largely independent effects of exposure to arsenic although glucosuria had some tendency to be associated with skin lesions. Importantly, however, glucosuria (diabetes mellitus) may occur independently of skin lesions.

 

     

Arsenic Exposure, Dermatological Lesions, Hypertension, and Chromosomal Abnormalities among People in a Rural Community of Northwest Iran

Chronic exposure to arsenic compounds is one of the major public-health problems in many developing and some developed countries. The aim of this study was to investigate the effects of chronic exposure to arsenic on dermatological lesions, hypertension, and chromosomal abnormalities among people in a community in the northwest of Iran. The occurrence of dermatological lesions, hypertension, and chromosomal abnormalities was investigated in two groups: Ghopuz village, including 101 subjects with chronic exposure to arsenic in drinking-water and Mayan village, including 107 subjects with no exposure. Daily/yearly absorbed amounts of arsenic were calculated for all subjects. Cumulative arsenic index for each individual was then estimated on the basis of age, water consumption, and location of residence. Arsenic concentration in drinking-water sources in Ghopuz and Mayan villages was 1031±1103 μg/L and non-detectable respectively. The mean systolic blood pressure in the exposure group [n=137, 95% confidence interval (CI 132–142)] was significantly higher than that in the control group (n=107, 95% CI 99.9–114). A similar significant difference was observed for diastolic blood pressure (exposed: n=82, 95% CI 79–85 vs non-exposed: n=71, 95% CI 66–75). The incidence of hyperkeratosis was 34 times higher among the exposure group compared to the control subjects [odds ratio (OR)=34, p<0.001)]. A significant difference was also observed in the occurrence of skin-pigmentation between the two groups (OR=2.4, p<0.007). Location and severity of the pigmentations were statistically different between the two groups. Twenty-five percent of the subjects in the exposure group showed chromosomal abnormalities (p=0.05). Arsenic exposure was a serious health problem in the region. More studies are needed to investigate the long-term effects and dose-response relationship of arsenic in the region and similar areas. Wide-ranging monitoring programmes for drinking-water sources should be implemented by public-health authorities.Key words: Arsenic, Cross-sectional studies, Dermatological lesions, Hypertension, Chromosomal abnormalities, Water pollution, Water supply, Iran     

Treatment adjustment and medication adherence for complex patients with diabetes, heart disease, and depression: a randomized controlled trial

PURPOSE

Medication nonadherence, inconsistent patient self-monitoring, and inadequate treatment adjustment exacerbate poor disease control. In a collaborative, team-based, care management program for complex patients (TEAMcare), we assessed patient and physician behaviors (medication adherence, self-monitoring, and treatment adjustment) in achieving better outcomes for diabetes, coronary heart disease, and depression.

METHODS

A randomized controlled trial was conducted (2007–2009) in 14 primary care clinics among 214 patients with poorly controlled diabetes (glycated hemoglobin [HbA_1c] ≥8.5%) or coronary heart disease (blood pressure >140/90 mm Hg or low-density lipoprotein cholesterol >130 mg/dL) with coexisting depression (Patient Health Questionnaire-9 score ≥10). In the TEAMcare program, a nurse care manager collaborated closely with primary care physicians, patients, and consultants to deliver a treat-to-target approach across multiple conditions. Measures included medication initiation, adjustment, adherence, and disease self-monitoring.

RESULTS

Pharmacotherapy initiation and adjustment rates were sixfold higher for antidepressants (relative rate [RR] = 6.20; P <.001), threefold higher for insulin (RR = 2.97; P <.001), and nearly twofold higher for antihypertensive medications (RR = 1.86, P <.001) among TEAMcare relative to usual care patients. Medication adherence did not differ between the 2 groups in any of the 5 therapeutic classes examined at 12 months. TEAMcare patients monitored blood pressure (RR = 3.20; P <.001) and glucose more frequently (RR = 1.28; P = .006).

CONCLUSIONS

Frequent and timely treatment adjustment by primary care physicians, along with increased patient self-monitoring, improved control of diabetes, depression, and heart disease, with no change in medication adherence rates. High baseline adherence rates may have exerted a ceiling effect on potential improvements in medication adherence.     

Incidence of transitional cell carcinoma and arsenic in drinking water: a follow-up study of 8,102 residents in an arseniasis-endemic area in northeastern Taiwan

A significant association between ingested arsenic and bladder cancer has been reported in an arseniasis-endemic area in southwestern Taiwan, where many households share only a few wells in their villages. In another arseniasis-endemic area in northeastern Taiwan, each household has its own well for obtaining drinking water. In 1991-1994, the authors examined risk of transitional cell carcinoma (TCC) in relation to ingested arsenic in a cohort of 8,102 residents in northeastern Taiwan. Estimation of each study subject's individual exposure to inorganic arsenic was based on the arsenic concentration in his or her own well water, which was determined by hydride generation combined with atomic absorption spectrometry. Information on duration of consumption of the well water was obtained through standardized questionnaire interviews. The occurrence of urinary tract cancers was ascertained by follow-up interview and by data linkage with community hospital records, the national death certification profile, and the cancer registry profile. Cox proportional hazards regression analysis was used to estimate multivariate-adjusted relative risks and 95% confidence intervals. There was a significantly increased incidence of urinary cancers for the study cohort compared with the general population in Taiwan (standardized incidence ratio = 2.05; 95% confidence interval (CI): 1.22, 3.24). A significant dose-response relation between risk of cancers of the urinary organs, especially TCC, and indices of arsenic exposure was observed after adjustment for age, sex, and cigarette smoking. The multivariate-adjusted relative risks of developing TCC were 1.9, 8.2, and 15.3 for arsenic concentrations of 10.1-50.0, 50.1-100, and >100 microg/liter, respectively, compared with the referent level of < or =10.0 microg/liter.     

Dietary Carbohydrate as Glycemic Load,Not Fat,Coupled with Genetic Permissiveness Favoring Rapid Growth and Extra Calories,Dictate Metabolic Syndrome and Diabetes Induction in Nile Rats (Arvicanthis niloticus)

Objective: Whether dietary carbohydrate (CHO) or fat is more involved in type 2 diabetes (T2DM) induction uncomplicated by dietary fiber was addressed in a spontaneous diabetic model, the diurnal Nile rat that mimics the human condition. Methods: A total of 138 male Nile rats were fed plant-based and animal-based saturated fat where 10% energy as CHO and fat were exchanged across 5 diets keeping protein constant, from 70:10:20 to 20:60:20 as CHO:fat:protein %energy. Diabetes induction was analyzed by: 1. diet composition, i.e., CHO:fat ratio, to study the impact of diet; 2. quintiles of average caloric intake per day to study the impact of calories; 3. quintiles of diabetes severity to study the epigenetic impact on diabetes resistance. Results: High glycemic load (GLoad) was most problematic if coupled with high caloric consumption. Diabetes severity highlighted rapid growth and caloric intake as likely epigenetic factors distorting glucose metabolism. The largest weanling rats ate more, grew faster, and developed more diabetes when the dietary GLoad exceeded their gene-based metabolic capacity for glucose disposal. Diabetes risk increased for susceptible rats when energy intake exceeded 26 kcal/day and the GLoad was >175/2000 kcal of diet and when the diet provided >57% energy as CHO. Most resistant rats ate <25 kcal/day independent of the CHO:fat diet ratio or the GLoad adjusted to body size. Conclusion: Beyond the CHO:fat ratio and GLoad, neither the type of fat nor the dietary polyunsaturated/saturated fatty acid (P/S) ratio had a significant impact, suggesting genetic permissiveness affecting caloric and glucose intake and glucose disposition were key to modulating Nile rat diabetes. Fat became protective by limiting GLoad when it contributed >40% energy and displaced CHO to <50% energy, thereby decreasing the number of diabetic rats and diabetes severity.     

Long-term noise exposure and the risk for type 2 diabetes: A meta-analysis

Diabetes mellitus is one of the leading causes for disability and mortality in modern societies. Apart from personal factors its incidence might be influenced by environmental risks such as air pollution and noise. This paper reports a systematic review and meta-analysis on the risk for type 2 diabetes due to long-term noise exposure. Electronic searches in MEDLINE, EMBASE and the Internet yielded 9 relevant studies (5 for residential and 4 for occupational exposure). They were checked against a predefined list of safeguards against bias producing individual quality scores, which were then fed to MetaXL to conduct a quality effects meta-analysis. People exposed at their homes to roughly L_den > 60 dB had 22% higher risk (95% confidence interval [CI]: 1.09-1.37) for type 2 diabetes in comparison to those exposed to L_den < 64 dB; when studies reporting contentious exposure categories were excluded, there was still 19% risk (95% CI: 1.05-1.35) for L_den = 60-70 dB versus L_den < 60 dB. In occupational environment there was not significant risk (relative risk [RR] = 0.91, 95% CI: 0.78-1.06) for < 85 dB versus >85 dB. There was no heterogeneity in the two groups (I² = 0.00). The results should be interpreted with caution due to methodological discrepancies across the studies; however, they are indicative of the close links that noise pollution might have not only to cardiovascular diseases but to endocrine dysfunction as well.     

Symptoms of depression as a risk factor for incident diabetes: findings from the National Health and Nutrition Examination Epidemiologic Follow-up Study, 1971-1992

Symptoms of depression may predict incident diabetes independently or through established risk factors for diabetes. US men and women aged 25-74 years who were free of diabetes at baseline (n = 6,190) were followed from 1971 to 1992 (mean, 15.6 years; standard deviation, 6) for incident diabetes. Depressive symptoms were measured by using the General Well-Being Depression subscale and were categorized to compare persons with high (9%), intermediate (32%), and low (59%) numbers of symptoms. The incidence of diabetes was highest among participants reporting high numbers of depressive symptoms (7.3 per 1,000 person-years) and did not differ between persons reporting intermediate and low numbers of symptoms (3.4 and 3.6 per 1,000 person-years, respectively) (p < 0.01 for high vs. low). In the subset of participants with less than a high school education (a marker of low socioeconomic status), the risk of developing diabetes was three times higher (95% confidence interval: 2.0, 4.7) for persons reporting high versus low numbers of depressive symptoms. These results persisted following adjustment for established diabetes risk factors. Depressive symptoms had no impact on diabetes incidence among persons with at least a high school education. Results suggest an independent role for depressive symptoms in the development of diabetes in populations with low educational attainment.     

Arsenic speciation analysis of urine samples from individuals living in an arsenic-contaminated area in Bangladesh

Objectives

Chronic inorganic arsenic (iAs) exposure currently affects tens of millions of people worldwide. To accurately determine the proportion of urinary arsenic metabolites in residents continuously exposed to iAs, we performed arsenic speciation analysis of the urine of these individuals and determined whether a correlation exists between the concentration of iAs in drinking water and the urinary arsenic species content.

Methods

The subjects were 165 married couples who had lived in the Pabna District in Bangladesh for more than 5 years. Arsenic species were measured using high-performance liquid chromatography and inductively coupled plasma mass spectrometry.

Results

The median iAs concentration in drinking water was 55 μgAs/L (range <0.5–332 μgAs/L). Speciation analysis revealed the presence of arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid in urine samples with medians (range) of 16.8 (7.7–32.3), 1.8 (<0.5–3.3), 13.7 (5.6–25.0), and 88.6 μgAs/L (47.9–153.4 μgAs/L), respectively. No arsenobetaine or arsenocholine was detected. The concentrations of the 4 urinary arsenic species were significantly and linearly related to each other. The urinary concentrations of total arsenic and each species were significantly correlated with the iAs concentration of drinking water.

Conclusions

All urinary arsenic species are well correlated with each other and with iAs in drinking water. The most significant linear relationship existed between the iAs concentration in drinking water and urinary iAs + MMA concentration. From these results, combined with the effects of seafood ingestion, the best biomarker of iAs exposure is urinary iAs + MMA concentration.     

Peer Reviewed: The Effect of Advanced Access Implementation on Quality of Diabetes Care

Introduction

The study analyzes the effect of an advanced access program on quality of diabetes care.

Methods

We conducted this study in a medical group of 240,000 members served by 17 primary care clinics. Seven thousand adult patients older than 18 years of age with diabetes were identified from administrative databases. Two aspects of advanced access — wait time for appointments and continuity of care — were calculated yearly for each patient during 1999 through 2001. We developed three composite measures of glucose and lipid control — process (proportion of patients with appropriate testing rates of hemoglobin A1c [HbA1c] and low-density lipoprotein [LDL]), good control (proportion with HbA1c < 8% and LDL < 130 mg/dL) and excellent control (proportion with HbA1c < 7% and LDL < 100 mg/dL) — and assessed them each year for each patient. We used multilevel logistic regression to predict the measures in 2000 and 2001 (years during and after advanced access implementation) relative to 1999 (year pre-advanced access).

Results

After implementation of advanced access, wait time decreased from 21.6 days to 4.2 days, and continuity improved by 6.5% (both P <.01). The percentage of patients with HbA1c < 7% increased from 44.4% to 52.3% and with LDL < 100 mg/dL from 29.8% to 38.7%. Increased continuity predicted improved process (P = .01), good control (P = .033), and excellent control (P <.001). However, wait time did not significantly predict process (P = .62) or quality measures (P = .95).

Conclusion

Measures of the quality of diabetes control improved in the year after implementation of advanced access, but better care did not correlate with decreased wait time to see a provider. However, improved continuity of care predicted improvements in both process and quality of diabetes care.     

Associations between Vitamin B-12 Status and Oxidative Stress and Inflammation in Diabetic Vegetarians and Omnivores

Diabetes is considered an oxidative stress and a chronic inflammatory disease. The purpose of this study was to investigate the correlations between vitamin B-12 status and oxidative stress and inflammation in diabetic vegetarians and omnivores. We enrolled 154 patients with type 2 diabetes (54 vegetarians and 100 omnivores). Levels of fasting glucose, glycohemoglobin (HbA1c), lipid profiles, oxidative stress, antioxidant enzymes activity, and inflammatory makers were measured. Diabetic vegetarians with higher levels of vitamin B-12 (>250 pmol/L) had significantly lower levels of fasting glucose, HbA1c and higher antioxidant enzyme activity (catalase) than those with lower levels of vitamin B-12 (≤250 pmol/L). A significant association was found between vitamin B-12 status and fasting glucose (r = −0.17, p = 0.03), HbA1c (r = −0.33, p = 0.02), oxidative stress (oxidized low density lipoprotein-cholesterol, r = −0.19, p = 0.03), and antioxidant enzyme activity (catalase, r = 0.28, p = 0.01) in the diabetic vegetarians; vitamin B-12 status was significantly correlated with inflammatory markers (interleukin-6, r = −0.33, p < 0.01) in diabetic omnivores. As a result, we suggest that it is necessary to monitor the levels of vitamin B-12 in patients with diabetes, particularly those adhering to a vegetarian diet.