Association of Hypothyroidism with Body Mass Index, Systolic Blood Pressure and Proteinuria in Diabetic Patients: Does treated Hypothyroidism with Thyroxine Replacement Therapy Prevent Nephropathy/Chronic Renal Disease?

Untreated or sub-clinical hypothyroidism is associated with insulin resistance, obesity, adverse effects on cardiovascular system, hypertension and in turn risk of nephropathy. However, these changes are reversible with thyroxine replacement therapy (TRT). Current research studied 4235 diabetic patients, divided into two groups, those with clinical hypothyroidism /on TRT, compared to those without thyroid disease or undiagnosed. BMI, blood pressure, creatinine, urine microalbumin and spot urine protein levels were compared between these two groups. Study finding demonstrated that for hypothyroid cases, BMI was higher (32.2 +/- 7.44 versus 29.4 +/- 5.7; p < 0.0001), serum creatinine was on lower levels (0.75 +/- 0.27 versus 1.0 +/- 0.74; p = 0.001), systolic BP was on lower side (123.7 +/- 15.9 versus 128.13 +/- 16.8; p= 0.015); spot urine microalbumin was on lower side (52.58 +/- 71.65; versus 87.77 +/- 140.86; p= 0.010) and spot urine protein had lower levels (25.3 +/- 38.3 versus 44.28 +/- 123.58; p < 0.0001). Current research also demonstrated that Pearson's chi(2) and odds/protective odds for hypothyroidism (on TRT) was strongly associated with obesity (p < 0.0001; odds ratio 2.28, 95% CI 1.47 to 3.56). However, they were protected from HTN (p= 0.272; protective odds ratio 1.28, 95% CI 0.824 to 1.98), nephropathy (p= 0.386; protective odds 1.36, 95% CI 0.861 to 2.14) and chronic renal disease (p= 0.112; protective odds 3.42, 95% CI 0.83 to 14.13). In conclusion, TRT itself has protective effects on cardiovascular and renal system. Hence, thyroid screening is essential among diabetics to detect sub clinical or clinical hypothyroidism.