The Association Between Subclinical Hypothyroidism and Sleep Quality: A Population-Based Study

BACKGROUND AND AIM: The relationship between subclinical hypothyroidism (SHYPO) and sleep quality is still unclear. Our objective was to compare the sleep quality between SHYPO patients and a control group with normal thyroid function. METHODS: A total of 2224 patients with SHYPO and 12,622 euthyroid (EUTH) control group patients were included in the present study. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. The sleep outcomes were compared to explore the association between SHYPO and sleep quality. Furthermore, we tried to identify the risk factors of poor sleep in SHYPO patients. RESULTS: Compared to the EUTH control patients, SHYPO patients had a higher PSQI score (6.83 ± 2.67 vs 6.64 ± 2.63, p =0.004) and a higher proportion of poor sleepers (67.09% vs 64.75%, p =0.033). Moreover, subjects with SHYPO were associated with poorer sleep (Odd Ratio (OR) 1.120, 95% Confidence Intervals (CI) 1.016 to 1.235, p =0.023), longer sleep latency (OR 1.162, 95% CI 1.053 to 1.282, p =0.003), and shorter sleep duration (OR 1.148, 95% CI 1.019 to 1.293, p =0.023) after adjusting for potential confounders. Furthermore, we found that lower age, lower body mass index, and women were risk factors for poor sleep quality in SHYPO patients. CONCLUSION: Our findings suggest a relationship between SHYPO and poor sleep quality in a large Chinese population.