Endocrine Abstracts

Background

Dyslipidemia is relevant association of hypothyroidism and consists of raised levels of total cholesterol, apolipoprotein B, triglycerides, low density lipoprotein (LDL) cholesterol, and reduced levels of high density lipoprotein (HDL) cholesterol.Thyroid hormones also have a role in modulating glucose metabolism and insulin resistance. The aim of study was to assess glycemic status, Homeostasis model assessment–estimated Insulin Resistance (HOMA–IR), and fasting lipid profile in individuals with newly detected overt primary hypothyroidism and to evaluate HOMA –IR, glycemic status and fasting lipid profile after achieving euthyroid status.

Methods

54 interested participants with Overt Primary hypothyroidism attending clinic from October 2017 to May 2019 were included. Individuals with diabetes, individuals on treatment for dyslipidemia or on treatment which can affect weight like steroids, anticonvulsants were excluded. Parameters were compared before and after achieving euthyroid state.

Results

Mean age of participants was 42.37±16.45 years. 79.6% were women. The mean duration to achieve euthyroid state was 8.626+0.782 weeks. The mean TSH before initiation of Levothyroxine was 27.55 µIU/l and after achieving euthyroid state was 2.63 µIU/l. The mean BMI before and after treatment was 23.83 ± 2.32 kg/m2 vs 22.87 ± 1.82 kg/m2 which was statistically significant.There was a statistically significant reduction in FPG, PPPG, HbA1c after treatment. The mean FBS before and after treatment were 123.50 ± 35.7 vs 95.31 ± 11.45 mg/dl, PPBS was 137.76 ± 42.98 vs 107.02 ± 18.55 mg/dl, and HbA1c 5.55 ± 0.90 ± 5.09 ± 0.53 %. There was a statistically significant difference found in TC, TG, LDL before and after achieving euthyroid state. The mean TC, TG LDL(mg/dl) before and after treatment were 173.09 ± 42.4 vs 144.83 ± 28.15, 156.20 ± 95.29 vs 103.76 ± 37.33, 110.02 ± 36.01 vs 85.84 ± 26.43 (P <0.001) respectively. The mean HDL before and after treatment was 41.74 ± 12.51 vs 44.00 ± 9.73 (P value 0.097). The mean HOMA – IR and fasting insulin before and after treatment were 3.60 ± 3.02 vs 1.84 ± 0.61, 10.42 ± 6.26 vs 7.91 ± 2.73 respectively and the difference was statically significant. FBS, PPBS, HbA1c, Total cholesterol, Triglycerides, LDL, HOMA IR, Fasting insulin all had positive correlation with TSH and were statistically significant.

Conclusion

Levothyroxine replacement is associated with significant improvement in insulin sensitivity and significant reduction in BMI, total cholesterol, triglycerides, low density lipoprotein, however HDL-C increase did not meet statistical significance.

Keywords

Hypothyroidism, HOMA-IR, Dyslipidemia.