Risk factors of ischemic heart disease among hypothyroid patients in Bangladesh

Background: Hypothyroidism in patients with cardiac diseases is associated with worse outcomes. However, this has not yet been adequately investigated in Bangladeshi people. 

Objective: To find out the Risk Factors of Ischemic Heart Disease Patients Among Hypothyroid Patients 

Materials and methods: This cross-sectional observational study, conducted at the Department of Endocrinology and Allied Medicine, BIRDEM General Hospital, recruited 90 consecutive patients with ischemic heart disease but no prior history of hypothyroidism. Serum levels of TSH, FT4, and anti-thyroid peroxidase (TPO) antibodies were measured using an automated analyzer with a chemiluminescent immunoassay method. Subclinical hypothyroidism (SCH) was defined as a TSH level between 4.12 mIU/L and 10 mIU/L, while overt hypothyroidism was defined as a TSH level above 10 mIU/L. We used chi-square tests, the independent sample t-test, One-way ANOVA, The significance level was set at p < 0.05.

Results: Of the 90 enrolled participants, 68 (75.6%) were euthyroid, 15 (16.7%) had subclinical hypothyroidism (SCH), and 7 (7.8%) had overt hypothyroidism. Of the patients with hypothyroidism, 7(31.8%) were anti-TPO antibody positive. Hypothyroidism was significantly more prevalent in females, non-smokers, obese individuals, those with HbA1c ≥ 10%, and patients with LVEF < 50%. In the hypothyroid group, mean ± SD systolic blood pressure, diastolic blood pressure, BMI, and HbA1c were also significantly higher. Although 95.5% of hypothyroid patients had dyslipidemia, there were no significant differences observed in specific lipid profiles between hypothyroid and euthyroid patients. Heart failure patients showed significantly more hypothyroidism and lower mean ± SD FT4 compared to patients without heart failure. Interestingly, mean ± SD TSH was significantly lower in females and the hypothyroid group. Predictors for hypothyroidism in IHD patients were female gender, non-smoker, higher BMI, higher SBP, and HbA1c ≥10%. Among these, the strongest predictor was BMI with an odds ratio of 7.920.

Conclusion: This study highlights the association between hypothyroidism and IHD, particularly in patients with the identified risk factors. It emphasizes the importance of screening for thyroid function in IHD patients, especially those with the mentioned characteristics.