Lower urinary albumin-to-creatinine ratio predicted all-cause and cardiovascular mortality in Chinese population with diabetes and prediabetes-The Shanghai Changfeng cohort study

IntroductionElevated urinary albumin-to-creatinine ratio (UACR) was associated with increased mortality in general population and diabetic patients. However, whether the association remains similar in the subjects with different status of glucose metabolism was unclear. Tthe optimal level of UACR in predicting mortality also remained unknown. This study aims to investigate the relationship between UACR with all-cause and cardiovascular mortality in population with different status of glucose metabolism and explore the predictive cutoff point of UACR.MethodsSix thousand three hundred and eighty-six community-dwelling individuals aged >= 45 years were enrolled and followed for an average of 5.3 years. Cox proportional hazards model was performed to analysis the association of baseline UACR and all-cause as well as cardiovascular mortality according to the status of glucose metabolism. Receiver operating characteristic curve was plotted to explore the optimal predictive cutoff point of UACR.ResultsWith UACR increasing, both the prevalence of all-cause and cardiovascular death increased. Cox analyses showed baseline UACR independently predicted the risk of all-cause and cardiovascular mortality in the patients with prediabetes mellitus (pre-DM) and diabetes mellitus (DM) but not in subjects with normal glucose tolerance (NGT). When divided by quartiles of UACR, the cumulative survival rate decreased acrossing the quartiles. Compared to the subjects with lowest quartile of UACR, participants with UACR >= 7.40 mg/gCr had a higher risk of all-cause mortality, and participants with UACR >= 16.60 mg/gCr had an increased risk of cardiovascular mortality in all hyperglycemia subjects. The optimal predictive cutoff point of UACR was about 17 mg/gCr.ConclusionUACR was an independent predictor of all-cause and cardiovascular mortality in population with pre-DM and DM but not in the subjects with NGT. The optimal predictive cutoff point of UACR is about 17 mg/gCr, which was far below the diagnostic cutoff point of microalbuminuria. Earlier interventions of albuminuria should be initiated from very early stage of hyperglycemia to reduce the burden of death in all patients whose glucose metabolism are impaired. HighlightsThe study firstly revealed that the relationship between UACR and mortality was different in subjects with different status of glucose metabolism. UACR was an important predictor of all-cause and cardiovascular mortality in patients with pre-DM and DM but not in subjects with normal glucose tolerance.The optimal cutoff point of UACR for prediction was about 17 mg/gCr, which was far below the current diagnostic cutoff point for microalbuminuria (30 mg/gCr).Earlier interventions of albuminuria should be initiated at much earlier stage of diabetic nephropathy, even at the normal stage of urine protein excretion, to ultimately reduce the burden of death in all the patients with hyperglycemia.image