Prevalence of thyroid dysfunction among patients with type 2 diabetes mellitus in Rajasthan and its association with heart rate variability parameters

Introduction: Many diabetic patients show features of thyroid dysfunction over a period of time. Although they are commonly claimed as coexistent, the significance of this apparent association has not been fully known. As the autonomic modulation is involved cardiovascular control, endocrine, and metabolic systems, a relationship between both conditions seems to provoke joint effects and increases cardiac autonomic impairments, hence, the cardiovascular risk. Therefore, this study aims to estimate the prevalence of thyroid dysfunction in the population of Rajasthan with type 2 diabetes mellitus and examine its association with heart rate variability parameters.Methods: A cross-sectional study conducted at department of Physiology in RUHS CMS Jaipur, on 270 patients with type 2 diabetes mellitus attending the out-patient department were recruited for the study. All subjects were screened for diabetes and thyroid dysfunction. Basic data (age, gender and ethnicity), anthropometric (height, weight, BMI waist-hip ratio), biochemical (FBS, HbA1c, lipid profile and thyroid profile) measurements were done in all subjects. Heart rate variability test was also done in all subjects.Results: Hypothyroidism was seen in 14.81%, while hyperthyroidism was observed in 5.19% of the study subjects. Thyroid dysfunction was more common among females than males. Glycemic, lipid profile and HRV parameters were more disturbed in subjects having both diabetes and thyroid dysfunction. There was significant correlation of diabetes and thyroid parameters with heart rate variability components.Conclusion: The prevalence of thyroid dysfunction was 20% in this study. Hypothyroidism was more common among the study subjects than hyperthyroidism.