The objective of this study was to find out about the correlation of obesity, TSH and HOMA-IR on Mexican obese patients.
Patients underwent screening assessment that included medical history, physical examination, vital signs and anthropometric measures.
Body mass index was calculated as weight in kilograms divided by the square of height in meters; HOMA-IR index was calculated as the product of basal glucose (mg/dL) and insulin levels (µIU/dL) divided by 405, normal range was considered up to 2.44.
T test was used when comparing two means. We conducted a Pearson correlation coefficient (r) to test linear relationship between variables: insulin resistance and thyroid status. Statistical significance was considered when p<0.05. All statistical analysis was performed on the Epidat 4.2 (T.M.) Software.
Of the 203 included patients 27 (13.3%) were men and 176 (86.7%) were women. Of these patients we found only 4 (1.97%) with overt hypothyroidism, defined as TSH levels >10mIU. There were also 16 (7.88%) patients with subclinical hypothyroidism, defined as serum TSH above 5mIU. Only one patient (0.49%) was found to be hyperthyroid with a TSH level of 0.0022mIU. All of whom were asymptomatic.
TSH levels were statistically significant (p= 4.52E^-09) different on patients with insulin resistance, as compared to those without.
When considering only those patients with insulin resistance, but no hypothyroidism, there were no significant correlations between TSH and the following: glucose (r=0.208), HOMA-IR (r=0.304), HbA1c (r=0.169) or insulin (r=0.298).
But when taking into account only those patients with insulin resistance and sub-clinical hypothyroidism, the correlations became stronger: TSH and glucose (r=0.048), and a negative correlation between TSH and insulin (r= -0.094), TSH and HOMA-IR (r= -0.099); the only non significant correlation was found to be TSH and HbA1c (r=0.881).
In Mexican obese patients who are insulin resistant, there is a significantly higher TSH value (6.31mIU/mL) when compared to non-insulin resistant obese patients (2.68mIU/mL). In the subset of obese Mexican patients with sub-clinical hypothyroidism there is a positive correlation between TSH levels and fasting plasma glucose, while the correlations are negative regarding TSH and insulin, and TSH and HOMA-IR. Further randomized controlled studies are required to confirm these observations.
Conclusion : There is a positive correlation between TSH levels and fasting plasma glucose, while the correlations are negative regarding TSH and insulin, and TSH and HOMA-IR. Suggesting an intricated relationship between these metabollic abnormalities.
Ramiro Balderas– Medical Director, Graber Center for Diabetes and Obesity, Mexico
Graber Center for Diabetes and Obesity, Mexico
Medical Degree at the Autonomous University of Hidalgo (México); Post-graduate training in Endocrinology and Diabetes at Queen Mary University of London; Master Degree in Clinical Nutrition at Jaen University (Spain).