Building an allostatic load index from data of occupational medical checkup examinations: a feasibility study

The allostatic load index (ALI) assesses the physiological adaption to chronic stress by cumulative changes in the circulation, respiration, inflammation, metabolic and anthropometric systems. The ALI thus can function as a risk marker for secondary prevention in occupational medicine. The aim of this study was to investigate the feasibility of creating a predictive marker by using data from an executive checkup program of an international company and to examine its relationship to work-related surrogate health parameters. Datasets from 307 examinations of 151 executives (19 males and 132 females) were available. Each participant attended at least one checkup examination between 2003 and 2015. The mean age was 43.6 (SD ±6.6, 31-64y). We developed four different ALIs with different biomarkers of the cardio-vascular, immune, metabolic and anthropometric systems. As a primary mediator, the thyroid-stimulating hormone was used as a proxy. For each ALI, the associations with the work ability index (WAI) and categories of sick leave days (SLD) were examined. Zero inflation was considered for SLD. One ALI showed a significant negative association with the WAI (B = -0.680, SE =0.266, p = .049). The results of a second ALI had a similar trend (B= -0.355, SE =0.201, p = .081). After adjustment for zero inflation two other ALIs showed a positive association with SLD. This study provides the first hints that biomarkers form a secondary prevention program are useful in calculating a meaningful ALI. Thus, the concept of allostatic load could be used in workplace health-promotion.