Background: There is strong biologic plausibility to support change in albuminuria as a surrogate endpoint for progression of chronic kidney disease (CKD), but empirical evidence to supports its validity in epidemiologic studies is lacking. Methods: We analyzed 28 cohorts including 693,816 individuals (80% with diabetes) and 7,461 end-stage kidney disease (ESKD) events, defined as initiation of kidney replacement therapy. Percent change in albuminuria was quantified during a baseline period of 1, 2 and 3 years using linear regression. Associations with subsequent ESKD were quantified using Cox regression in Coresh et al.

Microalbuminuria, an indicator of glomerular injury, is associated with increased risk of progressive renal deterioration, cardiovascular disease, and mortality. However, the prevalence of microalbuminuria in Japanese general population is less certain. Thus, we examined the prevalence of microalbuminuria and its associated risk factors in Japan. Subjects of this cross-sectional study were asymptomatic individuals over 40 years in Takahata, Japan. Urine albumin-creatinine ratio was calculated from a single-spot urine specimen collected in the morning. Creatinine clearance (CCr) was obtained by Cockcroft-Gault equation. Multivariate logistic regression analysis was used to determine which risk factors (i.e., age, hypertension, diabetes, obesity, and salt intake) might predict the presence of microalbuminuria. A total of 2321 subjects (mean age, 64 years; men, 1034; women, 1287) were entered into the final analysis. Among them, the prevalence of microalbuminuria, macroalbuminuria, and proteinuria by dipstick test (> or = 1+) were 317 (13.7%), 39 (1.7%), and 103 (4.4%), respectively. Age, hypertension, and diabetes were independently associated with microalbuminuria in men. In addition to the classical risk factors detected in men, estimated 24-h urinary sodium excretion and uric acid were also independently associated with microalbuminuria in women. Among the 668 subjects with renal insufficiency (CCr <60 ml/min/1.73 m(2)), the prevalence of microalbuminuria and macroalbuminuria were 119 (17.8%) and 18 (2.7%), respectively. In conclusion, microalbuminuria is prevalent across all age groups and is associated with lifestyle-related risk factors in Japanese general population. However, there are a substantial number of subjects with renal insufficiency accompanying no microalbuminuria.

Trace proteinuria could be a useful indicator of microalbuminuria in the general population, and especially in subjects at high risk of cardiovascular disease.

Objective

Hyperuricemia is associated with all-cause and cardiovascular mortality. However, the threshold value of serum uric acid levels for increased risk of mortality has not been determined. this large-scale cohort study used a nationwide database of 500,511 Japanese subjects (40-74 years) who participated in the annual health checkup and were followed up for 7 years. The association of serum uric acid levels at baseline with cardiovascular and all-cause mortality was examined. the cox proportional hazard model analysis with adjustment for possible confounders revealed that the all-cause and cardiovascular mortality showed a J-shaped association with serum uric acid levels at baseline in both men and women. A significant increase in the hazard ratio for all-cause mortality was noted with serum uric acid levels ≥ 7 mg/dL in men and ≥ 5 mg/dL in women. A similar trend was observed for cardiovascular mortality. this study disclosed that even a slight increase in serum uric acid levels was an independent risk factor for all-cause and cardiovascular mortality in both men and women in a community-based population. Moreover, the threshold values of uric acid for mortality might be different for men and women.Hyperuricemia is an established risk factor for gout and end-stage kidney disease 1 . Furthermore, various studies have suggested the association of hyperuricemia with all-cause and cardiovascular mortality 2-9 . However, the definition of hyperuricemia varies in each study; therefore, the threshold value of serum uric acid for increased risk of mortality, which is essential for the initiation of treatment, has not been determined.When examining the association between uric acid levels and prognosis, several points must be considered. First, hyperuricemia is often accompanied by other risk factors such as hypertension, obesity, diabetes, dyslipidemia, and renal insufficiency. This makes it difficult to determine whether hyperuricemia is an independent risk factor or a mere bystander with the other risk factors. Second, sex differences in the distribution of serum uric acid levels exist, and this may modify the association between serum uric acid levels and mortality 10-12 . Third, some studies showed that the association between serum uric levels and mortality was not linear, but J-shaped [11][12][13] , indicating that the conventional classification of uric acid levels, such as hyperuricemia (e.g., > 7 mg/dL) or per 1 mg/dL increase, might be inappropriate to evaluate the risk of increased serum uric acid levels on mortality.Considering these conditions, a large-scale study with a sufficient number of events, various correction factors, and a sex-specific reference range of uric acid is necessary to address this issue. However, in most previous studies, the conventional classification or quartile/quintile subgrouping of uric acid was used, and the number of events was insufficient to perform a multivariate analysis using a fine classification of uric acid levels. Accordingly, the association between uric acid levels and ...