Serum leptin and pituitary thyroid axis in hyperthyroid male patients

To see the correlation of serum leptin with pituitary-thyroid axis in hyperthyroid male patients and in euthyroid lean and obese control subjects. Four groups of males were included in the study, they comprised of 22 newly diagnosed, untreated hyperthyroid patients, 24 age, gender, BMI matched euthyroid lean subjects, 27 euthyroid obese subjects. Clinically and biochemically confirmed hyperthyroid patients were selected from the thyroid OPD of Atomic Energy Medical Centre, JPMC, Karachi. Healthy, age, gender, matched euthyroid [lean and obese] controls were selected from general population after checking their thyroid profile and clinical examination. Patients and controls suffering from diabetes or other endocrinal diseases and /or taking treatment for hyperthyroidism or steroids were excluded from the study. Ten ml of blood was drawn after an over night fast from each patient and control. Serum leptin was measured by EL1SA and FT4, FT3 and TSH were measured by radioimmunoassay [RIA], fasting blood sugar [FBS], triglycerides [TG], total cholesterol [TC], high density lipoprotein cholesterol [HDL-C] were checked by kit methods. Low density lipoprotein cholesterol [LDL-C] was calculated by the Friedwald's formula. The mean +/- SEM values of leptin in male hyperthyroid patients wasl.71 +/- 0.45 ng/ml, while in lean and obese control group it was 8.27 +/- 1.91 and 21.34 +/- 3.4 ng/ml respectively. In hyperthyroid patients, significantly low levels of serum leptin were found as compared to age, gender, BMI matched lean [p<0.005] and obese control group [p<0.005]. Obese control group had significantly higher values of leptin as compared to lean group [p<0.05]. No significant correlation of leptin was found with T4, T3, and TSH in hyperthyroid patients and lean and obese control subjects. Triglycerides [TG, p<0.005], total cholesterol [TC, p<0.005] and low dentistry lipoprotein cholesterol [LDL-C, p<0.05] were significantly lower in hyperthyroid patients as compared to control groups. Serum leptin level significantly correlated with the BMI [p<0.005], in hyperthyroid patients and euthyroid lean and obese control groups. There appears no relationship between serum leptin and pituitary thyroid axis in dysthyroid patients as well as in euthyroid subjects but it is strongly related with BMI in all subjects