Repeated Specific Health Guidance and improvement of metabolic syndrome in middle-aged working men: a longitudinal...

Metabolic syndrome (MetS) is a growing global health concern, and lifestyle interventions are important for preventing MetS and its progression to chronic diseases. Although short-term lifestyle interventions (typically within 12 months) have shown some improvements, clinically meaningful improvements in MetS and cardiovascular disease are achieved only in a subset of participants, indicating that many participants derive insufficient benefit. This study aimed to examine the effectiveness of repeated interventions for individuals who do not achieve sufficient weight loss with a short-term lifestyle intervention, using real-world data from Japan's health screening system, Specific Health Checkup (SHC) and Specific Health Guidance (SHG), by comparing outcomes between individuals who did not achieve sufficient improvement after the initial intervention and received and did not receive health guidance again in the following year.

This longitudinal observational study used 2018-2020 individual-level data of men aged 40-65 years from a Japanese health insurance database. Modified Poisson regression was used to investigate whether repeated SHG interventions for individuals who did not achieve sufficient improvement despite receiving SHG in fiscal year 2018 increased the probability of achieving ≥3% weight loss between 2019 and 2020.

The repeated and single intervention groups comprised 952 and 1,373 participants, respectively. No significant difference was observed between the groups in terms of ≥3% weight loss between 2019 and 2020 (16.0% vs. 13.5%; risk ratio [RR] = 1.18; 95% confidence interval [CI], 0.97-1.44, adjusted). Analyses stratified by stage of change showed a significant difference in the contemplation stage between the two groups (≥3% weight loss 2019-2020, 19.7% vs. 13.7%; RR = 1.47; 95% CI, 1.04-2.08).

No significant association was observed between repeated interventions and achieving ≥3% weight loss overall. An exploratory subgroup analysis suggested a possible benefit among individuals in the contemplation stage. These findings should be interpreted cautiously and confirmed in future studies.