Diabetes, especially type 2 diabetes (T2D), poses an unprecedented challenge to global public health. Hydration status also plays a fundamental role in human health, especially in people with T2D, which is often overlooked. This study aimed to explore the longitudinal associations between hydration status and the risk of T2D among the Chinese population. This study used data from the large community-based Kailuan cohort, which included adults who attended physical examinations from 2006 to 2007 and were followed until 2020. A total of 71,526 participants who eventually met the standards were divided into five hydration-status groups based on their levels of urine specific gravity (USG). Multivariable and time-dependent Cox proportional hazards models were employed to evaluate the associations of baseline and time-dependent hydration status with T2D incidence. Restricted cubic splines (RCS) analysis was used to examine the dose–response relationship between hydration status and the risk of T2D. Over a median 12.22-year follow-up time, 11,804 of the participants developed T2D. Compared with the optimal hydration-status group, participants with dehydration and severe dehydration had a significantly increased risk of diabetes, with adjusted hazard ratios (95% CI) of 1.30 (1.04–1.63) and 1.38 (1.10–1.74). Time-dependent analyses further confirmed the adverse effects of impending dehydration, dehydration, and severe dehydration on T2D incidence by 16%, 26%, and 33% compared with the reference group. Inadequate hydration is significantly associated with increased risks of T2D among Chinese adults. Our findings provided new epidemiological evidence and highlighted the potential role of adequate hydration status in the early prevention of T2D development.

Stroke is a documented risk factor for hip fracture(HF). However, no data is currently available on this issue in mainland China, we therefore assessed the risk of hip fracture after new-onset stroke using a cohort study. This study included 165,670 participants without a history of stroke at baseline from the Kailuan study. All participants were followed biennially until December 31, 2021. During follow-up, a total of 8,496 new-onset stroke cases were identified. For each case subject, four control subjects was randomly selected, matched for age (± 1 years) and sex. The final analysis comprised 42,455 pair-matched cases and controls. A multivariate Cox proportional hazard regression model was used to estimate the effect of new-onset stroke on the risk of hip fracture. During an average follow-up of 8.87 (3.94) years, a total of 231 hip fracture cases occurred, 78 cases in the stroke group and 153 cases in the control group, with incidence rates of 1.12 and 0.50 per 1000 person-years, respectively. The cumulative incidence of the stroke group was higher than that of the controls (P < 0.01). The adjusted hazard ratio (95% confidence interval) of hip fractures in the stroke group was 2.35 (1.77 to 3.12) (P < 0.001) to controls. After stratifying by gender, age, and body mass index, the higher risk was revealed in female (HR 3.10, 95 CI: 2.18 to 6.14, P < 0.001), age < 60 years old (HR 4.12, 95% CI: 2.18 to 7.78, P < 0.001), and non-obesity (BMI<28 kg/m²) (HR 1.74, 95% CI:1.31 to 2.31, P < 0.001) subgroup. Stroke significantly increases the risk of hip fracture, strategy for protecting stroke patients from falls and hip fractures should be emphasized in poststroke long-term management, particularly the female, age < 60 years old, and non-obese patients.