Chronic kidney disease prevalence and awareness in middle age and young old: Regional comparative study in Japan

Patients with chronic kidney disease are not aware of the illness because of its asymptomatic nature, but the association of disease progression and awareness in general population has not been sufficiently analysed on a large scale.

We analysed the nationwide annual specific health checkup covering more than a half of the overall population at aged 40-74 in Japan, approximately 29.4 million people as of 2018, in combination with parameters to represent regional characteristics.

The rate of the examinees with kidney dysfunction, an estimated glomerular filtration rate of <45 mL/min/1.73 m² , was 1.0%, while that of examinees with of dipstick proteinuria ≥ (+) was 3.7%. Next, we conducted a regional comparative study on 335 medical administrative areas divided in the country. The regional rate of examinees aged 65-74 over the total examinees was positively correlated with the prevalence of kidney dysfunction (r = 0.72, p < .0001). Additionally, the mean rate of examinees aware of their 'chronic kidney failure' was 0.6%, and the awareness rate was correlated with the prevalence of both kidney dysfunction (r = 0.36, p < .001) and positive dipstick proteinuria (r = 0.31, p < .001) in those aged 65-74 at the regional level. Association of nephrology care resources with the prevalence or awareness was unclear at the regional level.

We found a regional association of chronic kidney disease prevalence and awareness in a recent young old population in Japan. Further studies are needed to evaluate the patient screen and referral at the individual level.