Arsênico e diabetes

Arsenic Exposure and Prevalence of Type 2 Diabetes in US Adults
Ana Navas-Acien, MD, PhD; Ellen K. Silbergeld, PhD; Roberto Pastor-Barriuso, PhD; Eliseo Guallar, MD, DrPH
JAMA. 2008;300(7):814-822.
Context High chronic exposure to inorganic arsenic in drinking water has been related to diabetes development, but the effect of exposure to low to moderate levels of inorganic arsenic on diabetes risk is unknown. In contrast, arsenobetaine, an organic arsenic compound derived from seafood intake, is considered nontoxic.
Objective To investigate the association of arsenic exposure, as measured in urine, with the prevalence of type 2 diabetes in a representative sample of US adults.
Design, Setting, and Participants Cross-sectional study in 788 adults aged 20 years or older who participated in the 2003-2004 National Health and Nutrition Examination Survey (NHANES) and had urine arsenic determinations.
Main Outcome Measure Prevalence of type 2 diabetes across intake of arsenic.
Results The median urine levels of total arsenic, dimethylarsinate, and arsenobetaine were 7.1, 3.0, and 0.9 µg/L, respectively. The prevalence of type 2 diabetes was 7.7%. After adjustment for diabetes risk factors and markers of seafood intake, participants with type 2 diabetes had a 26% higher level of total arsenic (95% confidence interval [CI], 2.0%-56.0%) and a nonsignificant 10% higher level of dimethylarsinate (95% CI, –8.0% to 33.0%) than participants without type 2 diabetes, and levels of arsenobetaine were similar to those of participants without type 2 diabetes. After similar adjustment, the odds ratios for type 2 diabetes comparing participants at the 80th vs the 20th percentiles were 3.58 for the level of total arsenic (95% CI, 1.18-10.83), 1.57 for dimethylarsinate (95% CI, 0.89-2.76), and 0.69 for arsenobetaine (95% CI, 0.33-1.48).
Conclusions After adjustment for biomarkers of seafood intake, total urine arsenic was associated with increased prevalence of type 2 diabetes. This finding supports the hypothesis that low levels of exposure to inorganic arsenic in drinking water, a widespread exposure worldwide, may play a role in diabetes prevalence. Prospective studies in populations exposed to a range of inorganic arsenic levels are needed to establish whether this association is causal.

Vitamina D e Mortalidade: NHANES III

25-Hydroxyvitamin D Levels and the Risk of Mortality in the General Population
Michal L. Melamed, MD, MHS; Erin D. Michos, MD, MHS; Wendy Post, MD, MS; Brad Astor, PhD
Arch Intern Med. 2008;168(15):1629-1637.
Background In patients undergoing dialysis, therapy with calcitriol or paricalcitol or other vitamin D agents is associated with reduced mortality. Observational data suggests that low 25-hydroxyvitamin D levels (25[OH]D) are associated with diabetes mellitus, hypertension, and cancers. However, whether low serum 25(OH)D levels are associated with mortality in the general population is unknown.
Methods We tested the association of low 25(OH)D levels with all-cause, cancer, and cardiovascular disease (CVD) mortality in 13 331 nationally representative adults 20 years or older from the Third National Health and Nutrition Examination Survey (NHANES III) linked mortality files. Participant vitamin D levels were collected from 1988 through 1994, and individuals were passively followed for mortality through 2000.
Results In cross-sectional multivariate analyses, increasing age, female sex, nonwhite race/ethnicity, diabetes, current smoking, and higher body mass index were all independently associated with higher odds of 25(OH)D deficiency (lowest quartile of 25(OH)D level, <17.8>

Função renal e AVC

Impairment in Glomerular Filtration Rate or Glomerular Filtration Barrier and Occurrence of Stroke. Bruce Ovbiagele, MD .Arch Neurol. 2008;65(7):934-938.
Background Chronic kidney disease (CKD) is associated with substantial burden and is a strong risk factor for cardiovascular disease. However, data on the relationship between CKD and stroke are few and are limited by unreliable or inadequate assessment of renal function.
Objective To properly assess the relationship between renal insufficiency and stroke in stroke survivors in the United States by simultaneously examining the effect of guideline-recommended indices of renal disease that measure glomerular filtration rate (creatinine clearance) and glomerular filtration barrier (proteinuria).
Design Cross sectional.
Setting Nationally representative survey of the United States.
Subjects Participants aged 55 or older who participated in the National Health and Nutrition Examination Survey from 1999 to 2004.
Main Outcome Measures Indices of renal disease that measure glomerular filtration rate (creatinine clearance) and glomerular filtration barrier (microalbuminuria).
Results Of 6382 adults who met inclusion criteria, 5624 (88%) had full and complete data, of which 414 (6%) reported having had a stroke. Stroke survivors were older and more likely to have CKD, diabetes, hypertension, coronary artery disease, elevated blood pressure, increased glycohemoglobin concentration, and lower hematocrit compared with respondents who did not report stroke. Multivariate models showed that microalbuminuria (odds ratio, 1.51; 95% confidence interval, 1.02-2.24), decreased glomerular filtration rate (odds ratio, 1.93; 95% confidence interval, 1.28-2.91), and stage 3 CKD (odds ratio, 2.09; 95% confidence interval, 1.38-3.16) were significantly associated with stroke.
Conclusion Stroke is independently associated with impairment in structure and function of the glomerulus, which supports the need to consider screening patients with stroke for CKD and to simultaneously assess for both indices of renal disease