Should screening of renal markers be recommended in a working population?

Introduction: It is debated whether the general population should be screened for kidney disease. This study evaluated whether screening of albuminuria and estimated glomerular filtration rate (eGFR) in a working population should be recommended to detect subjects with chronic kidney disease.

Methods: The unreferred renal insufficiency study is a cross-sectional study in 1,398 workers aged 17-65. Markers of cardiovascular and renal disease were measured. Cardiovascular risk (CVR) was defined by hypertension (n = 416), diabetes (n = 45), dyslipidemia (n = 159) and/or history of a cardiovascular event (n = 10).

Results: In our population, 5 % of the workers had microalbuminuria, 0.5 % had macroalbuminuria and <0.1 % had eGFR <60 ml/min/1.73 m(2). All workers with an eGFR <60 ml/min/1.73 m(2) and/or macroalbuminuria (8/8) had at least one CVR factor, whereas this was the case in only half of workers with microalbuminuria (36/73, p = 0.007). In workers without CVR factors, the presence of microalbuminuria was associated with low body mass index (BMI, p < 0.001) or physiochemical exposure risk (p < 0.001).

Conclusions: Screening of renal markers in a working population, identified only a few subjects with an eGFR <60 ml/min/1.73 m(2) or macroalbuminuria. Although microalbuminuria was more prevalent, it might not necessarily indicate kidney disease, as it may have a completely different meanings depending of the phenotype of the screened subjects. Besides underlying CVR factors, microalbuminuria was also associated with low BMI in absence of any risk factor, suggesting presence of benign postural proteinuria. In addition, microalbuminuria also seemed to be related to physicochemical exposure. In view of the impossibility to further analyze this finding in the present study, the meaning of this observation needs to be further investigated.