Concentrations of the pesticide DDT (dichlorodiphenyltrichloroethane) and its metabolite
DDE (dichlorodiphenyldichloroethylene), in the blood of Mexican Americans, were evaluated
to determine their relationships with diabetes and diabetic nephropathy. The data
were derived from the National Health and Nutrition Examination Survey (NHANES) 1999-2004
(unweighted N = 1,411, population estimate = 13,760,609). The sample included teens,
12-19 years old, which accounted for 19.8% of the data. The time of the study overlapped
the banning of DDT in Mexico in the year 2000, and those participants born in Mexico
were exposed to DDT before they immigrated to the US. We sought to better understand
the relationship of DDT with diabetes in a race/ethnicity group prone to develop diabetes
and exposed to DDT. In this study, nephropathy was defined as urinary albumin to creatinine
ratio >30 mg/g, representing microalbuminuria and macroalbuminuria, and total diabetes
was defined as diagnosed and undiagnosed diabetes (glycohemoglobin, A1c ≥ 6.5%). The
proportion with the isomer p,p'-DDT >0.086 ng/g (above the maximum limit of detection)
was 13.3% for Mexican Americans born in the US, and 36.9% for those born in Mexico.
Levels of p,p'-DDT >0.086 ng/g were associated with total diabetes with nephropathy
(odds ratio = 4.42, 95% CI 2.23-8.76), and with total diabetes without nephropathy
(odds ratio = 2.02, 95% CI 1.19-3.44). The third quartile of p,p'-DDE (2.99-7.67 ng/g)
and the fourth quartile of p,p'-DDE (≥7.68 ng/g) were associated with diabetic nephropathy
and had odds ratios of 5.32 (95% CI 1.05-26.87) and 14.95 (95% CI 2.96-75.48) compared
to less than the median, respectively, whereas p,p'-DDE was not associated with total
diabetes without nephropathy. The findings of this study differ from those of a prior
investigation of the general adult US population in that there were more associations
found with the Mexican Americans sample.