Idiopathic post prandial glucose lowering, a whistle blower for subclinical hypothyroidism and insulin resistance. A cross-sectional study in Tertiary Care Centre of northeast India.

Abstract

There has been a lot of confusion in management of apparently healthy individuals whose post prandial plasma glucose levels were lower than fasting levels. It has been observed that many clinicians do send for repeat tests to rule out analytical error since there is common knowledge that post prandial glucose should be higher than fasting glucose level. Blood glucose level is regulated by a fully integrated mechanism with complex interplay of hormones and enzymes on metabolic pathways. Increase or decrease of thyroid hormones can break this equilibrium leading to alterations of carbohydrate metabolism. The objective for this study was to look for subclinical hypothyroidism (SCH) and insulin resistance (IR) in Idiopathic Post prandial glucose lowering and the correlation between thyroid stimulating hormone (TSH) with IR in them. A cross-sectional study with subgroup analysis, 34 cases and 34 controls. Cases comprises of otherwise healthy individuals whose post prandial glucose is lower than fasting glucose and controls as those healthy individual whose post prandial glucose is higher than fasting. Thyroid hormones and insulin were measured in fasting serum samples. Homeostasis model assessment for IR was calculated as per formula. Among the 34 cases with idiopathic post prandial glucose lowering, 76% (<i>n</i> = 26) had subclinical hypothyroidism and 61% (<i>n</i> = 21) had insulin resistance. A positive correlation (r = 0.55) was observed between Thyroid-Stimulating hormone (TSH) and Index of insulin resistance and homeostatic model assessment (HOMA-IR) and was statistically significant with <i>P</i> < 0.1. The study highlights the importance of evaluating glycoregulatory hormones like thyroid hormones and insulin in cases with idiopathic post prandial glucose lowering for early diagnosis and prevention of overt clinical diseases like Hypothyroidism and Diabetes Mellitus.