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

Background & objective: 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.

Methods: 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.

Results: 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).

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