**Background:** Periodic health checkups (PHCs) are a unique system in Japan designed for early detection of lifestyle-related diseases and cancer. However, the overall effectiveness of PHCs remains controversial, with meta-analyses showing no effect on all-cause mortality or cardiovascular death. Patients with type 2 diabetes mellitus (T2DM) have higher risks of cardiovascular disease, infections, and cancer, making them a population that might particularly benefit from PHCs. No prior studies had investigated the association between PHCs and hospitalization risk specifically in T2DM patients.
**Methods:** This retrospective cohort study was conducted at National Center for Global Health and Medicine (NCGHM), Kohnodai Hospital, Japan, from April 2013 to December 2015. A total of 1,256 patients with T2DM were enrolled. Patient data including CVD history, smoking (Brinkman index), alcohol consumption, exercise regularity, and whether PHCs were conducted were collected. Anthropometric measurements (BMI, waist circumference, blood pressure) and blood examinations (glucose, HbA1c, eGFR) were performed. Patients were followed for a mean of 857 ± 267 days (2.35 ± 0.73 years) until May 2016 or death. Cox proportional hazard analysis was performed adjusting for age, gender, BMI, CVD history, alcohol consumption, Brinkman index, exercise time, systolic and diastolic blood pressure, blood glucose, HbA1c, and eGFR. Post-hoc sample size estimation indicated 730 observations were needed for 80% power.
**Key Results:** Of 1,256 patients, 557 (44.3%) had undergone a PHC. During follow-up, 20 patients (1.6%) died, 14 (1.1%) sustained cardiovascular events, and 550 (43.8%) were hospitalized. In the PHC group, 213 patients (38.2%) were hospitalized at least once versus 337 (48.2%) in the non-PHC group. Total hospitalizations were 382 in the PHC group and 710 in the non-PHC group. The PHC group had significantly lower BMI (25.0 vs 25.8 kg/m², p = 0.013), smaller waist circumference (90.5 vs 93.2 cm, p = 0.001), fewer patients with CVD history (62 vs 112, p < 0.001), and fewer hospitalizations per patient (0.7 vs 1.0, p < 0.001). The PHC group also had higher alcohol consumption (19.3 vs 17.6 g/day, p = 0.032), more exercise time (18.7 vs 13.9 min/day, p = 0.003), and more walking time (31.4 vs 22.4 min/day, p < 0.001). Cox regression showed PHCs were significantly associated with lower hospitalization risk (HR = 0.825; 95% CI, 0.684–0.997; p = 0.046). No significant association was found between PHCs and CVDs (HR = 2.297; 95% CI, 0.667–7.910; p = 0.19) or all-cause mortality (HR = 1.461; 95% CI, 0.495–4.316; p = 0.49). Significant predictors of hospitalization included age (HR = 1.021 per year, p < 0.001), CVD history (HR = 1.304, p = 0.029), and HbA1c (HR = 1.340 per 1% increase, p < 0.001).
**Clinical Implications:** This study provides the first evidence that PHCs may reduce all-cause hospitalization risk in patients with T2DM by approximately 17.5%. The number needed to treat was 10, meaning PHCs need to be provided to 10 patients to prevent one additional hospitalization. The authors estimate that a general PHC (costing approximately ¥7,000 or $55 per examination) may be cost-effective for managing T2DM patients at higher hospitalization risk, whereas comprehensive health checkups (costing ¥57,000–¥64,000) may not be. The study highlights that patients who undergo PHCs tend to have higher health literacy, lower obesity rates, and more physical activity. However, limitations include lack of data on PHC components, detailed causes of hospitalization, objective dietary adherence measures, and socioeconomic status. The authors recommend targeting PHCs toward high-risk populations like T2DM patients and establishing standardized screening programs.