Increased prevalence of subclinical hypothyroidism in female hospitalized patients with depression

Sex differences in depressive disorder (DD) and subclinical hypothyroidism (SCH) have been well recognized. However, few studies focus on the sex differences in DD patients with SCH. The purpose of this study is to address the sex differences in DD inpatients with SCH and further investigate the clinical characteristics and associations between DD and SCH among female and male depressed inpatients.

A total of 1787 hospitalized patients with a diagnosis of DD were recruited. Depression was assessed using the Hamilton Depression Rating Scale-17 items (HAMD), and anxiety was assessed using the Hamilton Anxiety Rating Scale. Blood test, including serum thyroid hormone levels, was measured. According to different genders, associations between DD and the presence of SCH were estimated using binary logistic regression.

In the 1787 hospitalized patients with DD, the prevalence of SCH was 11.8%; the prevalence of SCH in female depressed inpatients is approximately two times that of male inpatients (14.6 vs. 7.4%, P < 0.05). Logistic regression showed that recurrent episodes and high BMI were associated with SCH in female inpatients (both P < 0.05). Spearman correlation analysis showed that thyroid stimulating hormone levels were associated with BMI (P < 0.05), total cholesterol levels (P < 0.05), and low-density lipoprotein cholesterol levels (P < 0.05) in female inpatients.

Our present study showed that the prevalence of SCH among female hospitalized patients with depression is approximately two times that of male inpatients. Recurrent and high-BMI female depressed inpatients are at high risk to develop SCH. More attention should be paid to the thyroid function of female inpatients with DD in future clinical work.