Job stress strengthens the link between metabolic risk factors and renal dysfunction in adult men

Chronic kidney disease (CKD) is an important risk factor for cardiovascular disease. The metabolic risk factors obesity, hypertension, diabetes, and dyslipidemia are closely associated with renal dysfunction. As psychosocial stress affects these risk factors, here, we examined relationships between metabolic risk factors and renal function, and their association with job stress. The participants were 1,231 Japanese male office workers attending annual health examinations. The estimated glomerular filtration rate (eGFR) was determined using the equation recommended by the Japanese Society for Nephrology: eGFR (mL/min/1.73 m(2)) = 194 × age(-0.287) × Cr(-1.094). Job stress was measured using the Job Content Questionnaire based on the job demand-control model. The job strain index equaled the job demand scores divided by the job control scores. The participants were classified into four ordinal groups of job strain index, based on previous studies (i.e., ≤ 0.4 the lowest, 0.4-0.5 lower, 0.5-0.6 higher, or ≥ 0.6 the highest). A significant correlation was found between lowered eGFR and each of the metabolic risk factors waist circumference, systolic and diastolic blood pressure, and total cholesterol (p < 0.001). Furthermore, job stress had an interactive effect on the relationships between eGFR and systolic and diastolic blood pressure, and triglycerides, depending on the job strain index (highest vs. lowest) (p < 0.05). The highly stressed workers exhibited a close association of eGFR with metabolic risk factors like hypertension and dyslipidemia. Therefore, intensive management may be important for preventing the progression of renal dysfunction and cardiovascular complications in those experiencing stress.