Serum C-reactive Protein Levels about Insulin Resistance and Beta Cell Function in Iranian Women with Subclinical Hypothyroidism

Subclinical hypothyroidism (SCH), is defined as an asymptomatic state characterized by a normal serum concentration of free thyroxine and elevated serum concentration of TSH. This study aims to investigate the complex interplay between hyperinsulinism, insulin resistance, beta cell function, and low-grade chronic inflammation in Iranian women with SCH.

Eighty women with SCH and 80 healthy women as controls matched to the patient group for sex, age, and body mass index (BMI), were enrolled in this prospective cross-sectional study. TSH, free T3, free T4, highly sensitive C-reactive protein (hs-CRP), fasting insulin, fasting glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, Triglyceride, HOMA-IR index, Beta cell function (HOMA-B index) and insulin sensitivity were determined.

Hs-CRP was not statistically different between the SCH patients and the control group (3.7±3.2 Vs 3.6±4.0, P>0.05). Total cholesterol and LDL-cholesterol were significantly higher; however, triglyceride and HDL-cholesterol were not statistically different in patients with SCH as compared with the control group. Fasting insulin levels and HOMA-IR and Beta cell function (HOMA-B) were significantly higher in SCH women compared to the control group. A positive correlation between HOMA-IR and HOMA-B with TSH levels was found (r=0.324, r=0.191, P<0.05 respectively). A positive correlation between insulin levels and hs-CRP (r=0.22, P<0.05), also between insulin levels and TSH (r=0.312, P<0.05) and LDL- LDL-cholesterol was obtained (r=0.27, P<0.05).

Iranian women with SCH may exhibit elevated atherogenic parameters (hyperinsulinemia, LDL-cholesterol, and total cholesterol), HOMA-IR, and HOMA-B.