The multimorbidity of hypertension and osteoarthritis and relation with sleep quality and hyperlipemia/hyperglycemia in China's rural population.

Hypertension (HTN) and osteoarthritis (OA) are frequent in middle-aged and elderly people, and the co-occurrence of these two diseases is common. However, the pathogenesis of the multimorbidity of both diseases and the relation with sleep quality, hyperlipemia, and hyperglycemia is unclear. We conducted a cross-sectional study to make sense of the multimorbidity of HTN and OA and the relation with sleep quality, hyperlipemia, and hyperglycemia. The relation between sleep quality and OA and its joint effect with hyperlipemia or hyperglycemia was evaluated with logistic regression models. The additive interaction was assessed with the relative excess risk due to interaction (REEI), the attributable proportion (AP), and the synergy index (S). According to this research in a remote rural area, approximately 34.2% of HTN patients are accompanied with OA and 49.1% are suffering poor sleep. Both hyperlipemia/hyperglycemia and sleep quality were related to OA prevalence with crude ORs of 1.43 (95% CI 1.014-2.029) and 1.89 (95% CI 1.411-2.519, P < 0.001) respectively. An observed additive effect was found greater than the sum of the effects of sleep quality and hyperlipemia/hyperglycemia posed on OA prevalence alone. This additive interaction was observed in females (OR = 3.19, 95% CI 1.945-5.237) as well as males ≥ 65 years old (OR = 2.78, 95% CI 1.693-4.557), with RERI, AP, and S significant. Therefore, poor sleep and hyperlipemia/hyperglycemia are associated with OA, and further studies on the additive interaction among females and males ≥ 65 are warranted.