Abstract
BACKGROUND: This study aimed to identify the factors relating to moderately increased albuminuria among middle-aged and older individuals in Japan. METHODS: We conducted specific health examinations in which we measured albuminuria levels, and administered a questionnaire survey to record participants' lifestyles in western Tokushima Prefecture, Japan. A total of 1,660 people whose albuminuria was less than 300 mg/g creatinine (Cr) were analyzed. We divided participants into two groups-those with normal albuminuria (< 30 mg/gCr) and those with moderately increased albuminuria (≥ 30 mg/gCr, > 300 mg/gCr)-and compared their characteristics. To investigate all relevant factors, we conducted a multivariate logistic regression analysis. RESULTS: The moderately increased albuminuria group were significantly older and had, among them, significantly higher percentages of a body mass index (BMI) ≥ 25 kg/m(2), diabetes, hypertension, and mild liver disorder (aspartate transaminase ≥ 31 U/L or alanine aminotransferase ≥ 31 U/L or gamma-glutamyl transferase ≥ 51 U/L). (p < 0.01) In a multivariate logistic regression analysis that used microalbuminuria as an independent variable, we found the adjusted odds ratio (AOR) and 95% confidence interval (CI) to be significantly higher among individuals with diabetes (AOR: 2.04, 95% CI: 1.40-2.99); hypertension (AOR: 1.90, 95% CI: 1.36-2.65); BMI ≥ 25 kg/m(2) (AOR: 1.76, 95% CI: 1.27-2.44); and mild liver disorder (AOR: 1.54, 95% CI: 1.10-2.18). CONCLUSIONS: In addition to diabetes, hypertension, and BMI ≥ 25 kg/m(2), this study found that among the middle-aged and older general population living in western Tokushima Prefecture, there were cases of mild liver disorder (elevated serum transaminase), which independently associated with moderately increased albuminuria. Therefore, in health checkups targeting the general population, there is a need to consider measuring albuminuria, even in those who have only mild liver dysfunction (health guidance level). TRIAL REGISTRATION: N/A.