Association between Metabolic Syndrome with Subclinical Hypothyroidism
Author(s): Sharmin Akter, Mohammad Maruf Reza
Introduction: The worldwide prevalence of metabolic syndrome in the adult population is on the rise and Bangladesh is not an exception. Metabolic syndrome is defined by a constellation of interconnected physiological, biochemical, clinical, and metabolic factors that directly increases the risk of cardiovascular disease, type 2 diabetes mellitus, and all causes of mortality.
Objective: To determine the association of subclinical hypothyroidism with metabolic syndrome.
Materials and methods: The present case-control study was conducted in the department of Internal Medicine, Rangpur Medical College Hospital, Rangpur, Bangladesh from January 2008 to December 2008. Patients of metabolic syndrome were considered as case, while apparently healthy individuals (having no hypertension, central obesity or dyslipidaemia) were taken as control. Metabolic syndrome was defined as having at least three criteria out of five criteria, as recommended by NCEP: ATPIII Diagnostic Criteria for Metabolic Syndrome, while subclinical hypothyroidism was defined, when TSH ranges from 4-20 mU/L with normal FT3 and FT4. Cases were selected from patients attending indoor and outdoor of Medicine Department of RMCH during the study period, while friends and relatives of cases of similar age and sex were selected as control.
Results: In the present study out of 70 cases 48(68.6%) had central obesity (waist circumference > 90 cm for male and > 80 cm for female), 57(81.4%) had raised triglycerides (TG ≥ 150 mg/dl), 61(87.1%) had raised blood pressure (≥130/85), 59(84.3%) had hyperglycemia (fasting blood glucose ≥ 100 mg/dl) and only 11(15.7%) had reduced HDL (<40 mg/dl for male and <50 mg/dl for female) three factors, namely subclinical hypothyroidism,BMI and socioeconomic status were observed to be significantly associated with metabolic syndrome in univariate analysis. After adjustment by binary logistic regression analysis, all these three variables remained to be significantly associated with metabolic syndrome with risk of having the condition being 2.3(95% CI = 0.9–5.8) times more in patients with subclinical hypothyroidism, 2.3(95% CI = 1.4–8.1) times higher in overweight/obese individuals and 2.8(95% CI = 1.3–5.8) times higher in affluent socioeconomic class (p=0.038, p=0.007 and p=0.006 respectively).
Conclusion: The study found that factors, namely subclinical hypothyroidism, BMI and socioeconomic status to be significantly associated with metabolic syndrome in univariate analysis. After adjustment by binary logistic regression analyses, patients of metabolic syndrome carry more than 2.7-fold higher risk of having subclinical hypothyroidism.