Insulin resistance and glucose levels in subjects with subclinical hypothyroidism

Objective: To compare insulin resistance and glycemic indicators among subjects with euthyroidism and subclinical hypothyroidism

Study Design: Comparative cross-sectional study

Place and Duration of Study: Department of Pathology and Medicine, PNS Hafeez, Islamabad, in collaboration with the Department of Chemical Pathology and Endocrinology at the Armed Forces Institute of Pathology [AFIP], Rawalpindi, from December 2015 to September 2016

Methodology: Subjects referred for executive screening of apparently healthy population [without any known history of diabetes, hypertension, heart disease or other chronic ailments], were included. Subjects were grouped as euthyroidism and subclinical hypothyroidism

Results: Median [IQR] insulin resistance indices including fasting insulin and Homeostasis Model Assessment for Insulin Resistance in subjects with group-1 [n=176, 87%, Thyroid Stimulating Hormone: 0.5 - 3.5 mlU/L] and group-2 [n=26, 13%, Thyroid Stimulating Hormone: 3.51 -15 mlU/L] were 7.6 [6.70] vs. 11.4 [13.72, p=0.040] and 1.77 [1.79] vs. 2.8 [3.07, p=0.071]

The median differences for fasting plasma glucose were 5.0 [1.0] in group-1 vs. 5.0 [1.47] for Group-2 [p=0.618], and glycated hemoglobin was 5.60 [1.1] vs. 5.60 [1.7, p=0.824]. Homeostasis Model Assessment for beta sensitivity index in paradox showed slightly higher values for group-2 [median [IQR] 86.67 [92.94]] than group-1 [111.6 [189.64, p= 0.040]]

Conclusion: Measures of insulin resistance including Homeostasis Model Assessment for Insulin Resistance and fasting insulin levels were significantly different between subjects with euthyroidism and having subclinical hypothyroidism

Estimated reference interval of ionized [free] calcium

To determine the reference values of Ca++ in whole blood in our setup. The Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology, Rawalpindi from Jan 2008 to June 2008. Three hundred healthy individuals were included in the study after obtaining written consent. Out of these 76 individuals were excluded from the study after clinical assessment and collection of laboratory data. One hundred and fourteen were males with mean age 35 +/- 12 years and 110 were females, with mean age 28 +/- 9 years of age. Their Ca++ was estimated by ion selective electrode [ISE] method in heparinized whole blood [WB]. The mean and SD of whole blood Ca++ was calculated separately for the females and the males. The results showed that in our setup males have Ca++ levels of 1.12 +/- 0.05 [mean +/- SD] mmol/l and females have Ca++ levels of 1.12 +/- 0.04 [mean +/- SD] mmol/l. The study revealed that estimated reference range of Ca++ of the studied population was lower than the reference range published for the western population that is used by our physicians for the interpretation and comparison of results