The Relation of Glycemic Control and Primary Hypothyroidism in Saudi Patients with Type 2 Diabetes Mellitus

Background and objective: The associations between diabetes and hypothyroidism have long been reported. Thus, we conducted a cross sectional study to find out the relationship between Type 2 Diabetes Mellitus (T2DM) and hypothyroidism in Saudi patients with T2DM. Design: A “cross-sectional study” was conducted in the Diabetes centre at King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia from January 2018 to December 2018. Thyroid Stimulating Hormone (TSH), Free Thyroxin (FT4) and HbA1c were measured. Results: A total of 1168 patients with T2DM were included in this study. Average age of the study population was 55.1 ± 16.2. Hypothyroidism was present in 92 (7.9 %) with males were non-statistically significant more prevalent than females in patients with HbA1c <7 and ≥ 7%. There was a trend up as age advanced with females were statistically significant more prevalent than males in the fifth decade (p=0.01). Patients with HbA1c ≥ 7 were statistically significant older compared to patients with HbA1c <7 (p=0.005) with females were statistically significant more prevalent in patients with HbA1c <7 and ≥ 7, (61.6 vs 38.4% and 75 vs 25%) respectively, p=<0.0001. TSH was statistically significant higher in patients with HbA1c ≥ 7 compared to patients with HbA1c <7 (p=0.02). FT4 was statistically significant lower in patients with HbA1c ≥ 7 compared to patients with HbA1c <7 (p=0.01). HbA1c was found to be an independent predictor of TSH level (P=0.02). A statistically significant positive correlation was observed between TSH and HbA1c (r=0.06, P=0.04). Also, a significant negative correlation was observed between FT4 and HbA1c (r=-0.068, P=0.03). Conclusion: The frequency of primary hypothyroidism was high with poor glycemic control in patients with T2DM.