Subclinical Hypothyroidism Is Independently Associated with Microalbuminuria in a Cohort of Prediabetic Egyptian Adults

BACKGROUND Recent evidence has suggested an association between subclinical hypothyroidism (SCH) and microalbuminuria in patients with type 2 diabetes. However, whether SCH is related to microalbuminuria among subjects with prediabetes has not been studied. Thus, we evaluated the association between SCH and microalbuminuria in a cohort of prediabetic Egyptian adults. METHODS A total of 147 prediabetic subjects and 150 healthy controls matched for age and sex were enrolled in this study. Anthropometric measurements, plasma glucose, lipid profile, homeostasis model assessment of insulin resistance (HOMA-IR), thyroid stimulating hormone (TSH), free thyroxine, triiodothyronine levels, and urinary albumin-creatinine ratio (UACR) were assessed. RESULTS The prevalence of SCH and microalbuminuria in the prediabetic subjects was higher than that in the healthy controls (16.3% vs. 4%, P<0.001; and 12.9% vs. 5.3%, P=0.02, respectively). Prediabetic subjects with SCH were characterized by significantly higher HOMA-IR, TSH levels, UACR, and prevalence of microalbuminuria than those with euthyroidism. TSH level was associated with total cholesterol (P=0.05), fasting insulin (P=0.01), HOMA-IR (P=0.01), and UACR (P=0.005). UACR was associated with waist circumference (P=0.01), fasting insulin (P=0.05), and HOMA-IR (P=0.02). With multiple logistic regression analysis, SCH was associated with microalbuminuria independent of confounding variables (β=2.59; P=0.01). CONCLUSION Our findings suggest that prediabetic subjects with SCH demonstrate higher prevalence of microalbuminuria than their non-SCH counterparts. SCH is also independently associated with microalbuminuria in prediabetic subjects. Screening and treatment for SCH may be warranted in those patients.