The specific relationship between vitamin D deficiency and diabetic nephropathy among patients with advanced chronic kidney disease: a cross-sectional study in Gran Canaria, Spain.

AIMS: Vitamin D deficiency is highly prevalent in subjects with advanced chronic kidney disease (CKD), but diabetes, the most common cause of CKD, has also been linked to low levels of serum 25-hydroxyvitamin D [25(OH)D]. We compare vitamin D status between subjects with type 2 diabetes-related advanced CKD and subjects with either advanced CKD without diabetes or type 2 diabetes without advanced CKD. METHODS: Subjects were patients with advanced CKD (estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2) from February 2011 to November 2013 (113 with diabetes-related CKD and 80 without diabetes) and 61 patients with long-lasting type 2 diabetes without advanced CKD, simultaneously enrolled from our center. Participants fulfilled a survey questionnaire and underwent physical examination, blood samples, and 24-h urine collection. Kidney disease was assessed using eGFR and 24-h urinary protein excretion. Serum 25(OH)D was measured by chemiluminescence immunoassay. RESULTS: The prevalence of vitamin D deficiency (25(OH)D < 20 ng/mL) was 70.8% in subjects with diabetes-related CKD, 38.8% in subjects with non-diabetic CKD and 41% in subjects with diabetes without advanced CKD. Adjusted means (95% confidence interval (CI)) of 25(OH)D in participants with diabetes-related CKD, in nondiabetic participants with CKD, and in participants with diabetes without advanced CKD were, respectively, 17.5 (14.2 - 20.7), 23.6 (19.4 - 27.8), and 23.5 (16.8 - 30.3) ng/mL (p = 0.023). CONCLUSIONS: Low vitamin D status is characteristically associated with advanced diabetic nephropathy. This relationship is not entirely attributable to the individual effects of CKD or long-lasting diabetes.

Potential implications of the choice among three alternative treatment targets for apolipoprotein B100 in the management of patients with type 2 diabetes and chronic kidney disease.

This study analyses discordance rates between attainment of therapeutic goals for apolipoprotein B100 (apoB) and both low-density lipoprotein-cholesterol (LDL-C) and non-high-density lipoprotein-cholesterol (non-HDL-C) in a sample of 152 patients with type 2 diabetes and chronic kidney disease from Gran Canaria (Spain), using treatment targets recommended by the American Diabetes Association/American College of Cardiology (ADA/ACC), the European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) and by a Spanish population-based study. Among subjects with LDL-C levels at therapeutic goal, apoB was above target in 16.3% (ADA/ACC), 6.5% (ESC/EAS) and 39.1% (population-based criteria), and among subjects with non-HDL-C levels at therapeutic goal, apoB was above target in 10.5% (ADA/ACC), 1.2% (ESC/EAS) and 29.6% (population-based criteria). These findings show that clinical management would be very differently altered depending on the criteria used to set treatment targets for apoB. Cut-off points derived from population data identify a greater number of subjects suitable for a more intensive lipid-lowering therapy.

Non-albuminuric renal disease among subjects with advanced stages of chronic kidney failure related to type 2 diabetes mellitus.

Urinary albumin excretion has been consistently found to be normal in a significant number of subjects with early stages of diabetic kidney disease. This study was aimed to estimate the prevalence and characteristics of non-albuminuric chronic kidney disease associated with type 2 diabetes mellitus among subjects who reach advanced stages of renal failure. Study population was composed of incident patients with advanced chronic kidney disease (glomerular filtration rate <30 mL/min) related to type 2 diabetes in a tertiary hospital from Gran Canaria (Spain) during a period of 2 years. Subjects were classified as normoalbuminuric (urinary albumin-to-creatine ratio [UACR] <30 mg/g), microalbuminuric (UACR ≥30 and <300 mg/g), or proteinuric (UACR ≥300 mg/g). Of 78 eligible patients, 21.8% had normoalbuminuria, 20.5% had microalbuminuria, and 57.7% had proteinuria. Individuals with normoalbuminuria were mostly women and had a lower prevalence of smoking and polyneuropathy than subjects with microalbuminuria or proteinuria. They also presented greater measures of body mass index and waist circumference, higher values of total and LDL cholesterol, and lower values of HbA1c and serum creatinine than subjects with microalbuminuria or proteinuria. Multivariate analysis demonstrated that female sex (positively) and HbA1c and polyneuropathy (negatively) were independently associated with absence of albuminuria. In conclusion, around 20% of subjects with diabetes-related advanced chronic kidney disease, characteristically women, have normal urinary albumin excretion. HbA1c and polyneuropathy are inversely related to this non-albuminuric form of nephropathy.