Left Ventricular Diastolic Dysfunction in Patients with Subclinical Hypothyroidism: A Single South Indian Tertiary Care Centre Study

Abstract

Context Subclinical hypothyroidism (SCH) has been implicated in left ventricular diastolic dysfunction (LVDD). Aims To study the association between SCH and LVDD. Objectives To analyze the association between SCH and LVDD. To correlate the amount of LVDD with the serum thyroid-stimulating hormone (TSH) levels. Settings and Design Single-center case–control study. Methods and Material A case–control study was conducted between January 2020 and June 2021. A total of 36 cases of SCH were enrolled in the study and 36 age- and gender-matched euthyroid controls were included. Each individual's LV diastolic functioning was assessed by 2D echocardiography. LVDD was graded and compared between cases and controls. Statistical Analysis Used The sample size was calculated to be 72 based on previous studies. Statistical analysis was performed using the IBM SPSS software version 20. A p-value of less than 0.05 was considered significant. Results SCH was more commonly seen among females (75%) as compared with males (25%). Among cases, a majority of them (75%) had grade 1 SCH (i.e., TSH < 10 mU/L) and 25% of them had grade 2 SCH (i.e., TSH ≥ 10 mU/L). Among all the parameters assessed for LV diastolic function, the isovolumetric relaxation time and septal E/e' ratio was found to be significantly higher in cases than in controls and mitral E wave deceleration time (DT) significantly lower in cases. A statistically significant majority (72.2%) of the patients with SCH had some form of LVDD as compared with controls (30.5%) Conclusions Walk-in outpatient department patients who opt for health check-up packages should be screened for SCH. SCH is statistically significantly associated with higher grades of LVDD as compared with age- and gender-matched euthyroid controls.