Molecular epidemiology of autoimmune thyroid disease.

This paper presents preliminary data regarding the prevalence and risk factors for autoimmune thyroid disease in IDDM probands ascertained from the Children's Hospital of Pittsburgh IDDM Registry for 1950-1965 (n = 669). Living IDDM probands who participated in the 1990 follow-up survey (n = 380) were recruited for the Familial Autoimmune and Diabetes Study. Siblings and parents were also invited to participate. To date, 255 IDDM probands and 597 parents and siblings have been evaluated. The diagnosis of autoimmune thyroid disease was based on a clinical evaluation, medical history, and laboratory determinations. Graves disease was rare in this cohort (n = 5). However, Hashimoto's thyroiditis was common among women. Prevalence rates ranged from 54% for IDDM women age < 40 years to 75% for those > 50 years. Corresponding age-specific estimates for female relatives were 22% and 44%, respectively. Approximately one-half of the Hashimoto's individuals were euthyroid; they were more likely to have other autoantibodies and a positive family history than those who were hypothyroid or had no thyroid disease. Genetic analyses revealed a 2-fold increase in DQA1*0501-DQB1*0201 among the Hashimoto's compared to the non-Hashimoto's haplotypes. These findings suggested that Hashimoto's thyroiditis was common in IDDM families, which may be due, in part, to common disease susceptibility genes.

Epidemiological correlates of diabetic neuropathy. Report from Pittsburgh Epidemiology of Diabetes Complications Study.

The natural history of diabetic neuropathy and its risk factors are not well understood, apart from the recognition that prevalence increases with duration and, in many studies, degree of glycemia. The role of potential risk factors was therefore evaluated in a cross-sectional analysis from the baseline examination of the Pittsburgh Epidemiology of Diabetes Complications Study. We present results from the first 400 subjects seen at baseline examination. Neuropathy was determined by a trained internist with a standardized examination and was defined as the presence of at least two of three criteria: abnormal sensory or motor signs, symptoms consistent with neuropathy, and decreased tendon reflexes. The prevalence of neuropathy in this cohort was 34% (18%, 18-29 yr old, 58% greater than or equal to 30 yr old) with no difference by sex. By focusing on subjects greater than or equal to 18 yr old, all significant univariate variables (e.g., duration, glycosylated hemoglobin [HbA1]) were analyzed in 3 multiple logistic regression models: all subjects greater than or equal to 18 yr old and separating the same subjects into two groups based on age (18-29 and greater than or equal to 30 yr). Duration, HbA1, smoking status, and high-density lipoprotein cholesterol were found to be associated with neuropathy in the models for the greater than or equal to 18-yr-old group and the greater than or equal to 30-yr-old group. In the 18- to 29-yr-old group, duration, HbA1, and hypertension status were found to be significantly associated with neuropathy.(ABSTRACT TRUNCATED AT 250 WORDS)