Urine cotinine versus self-reported smoking and the risk of chronic kidney disease

Background and hypothesis Evidence on the role of smoking in the development of chronic kidney disease (CKD) has mostly relied on self-reported smoking status. We aimed to compare the associations of smoking status as assessed by self-reports and urine cotinine with CKD risk. Methods Using the PREVEND prospective study, smoking status was assessed at baseline using self-reports and urine cotinine in 4333 participants (mean age, 52 years) without a history of CKD at baseline. Participants were classified as never, former, light current, and heavy current smokers according to self-reports and comparable cutoffs for urine cotinine. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated for CKD. Results The percentages of self-reported and cotinine-assessed current smokers were 27.5% and 24.0%, respectively. During a median follow-up of 7.0 years, 593 cases of CKD were recorded. In analyses adjusted for established risk factors, the HRs (95% CI) of CKD for self-reported former, light current, and heavy current smokers compared with never smokers were 1.17 (0.95–1.44), 1.48 (1.10–2.00), and 1.48 (1.14–1.93), respectively. On further adjustment for urinary albumin excretion (UAE), the HRs (95% CI) were 1.07 (0.87–1.32), 1.26 (0.93–1.70), and 1.20 (0.93–1.57), respectively. For urine cotinine-assessed smoking status, the corresponding HRs (95% CI) were 0.81 (0.52–1.25), 1.17 (0.92–1.49), and 1.32 (1.02–1.71), respectively, in analyses adjusted for established risk factors plus UAE. Conclusion Self-reported current smoking is associated with increased CKD risk, but dependent on UAE. The association between urine cotinine-assessed current smoking and increased CKD risk is independent of UAE. Urine cotinine-assessed smoking status may be a more reliable risk indicator for CKD incidence than self-reported smoking status.</p

Biochemical Urine Testing of Medication Adherence and Its Association With Clinical Markers in an Outpatient Population of Type 2 Diabetes Patients: Analysis in the DIAbetes and LifEstyle Cohort Twente (DIALECT)

OBJECTIVE To assess adherence to the three main drug classes in real-world patients with type 2 diabetes using biochemical urine testing, and to determine the association of nonadherence with baseline demographics, treatment targets, and complications.RESEARCH DESIGN AND METHODS Analyses were performed of baseline data on 457 patients in the DIAbetes and LifEstyle Cohort Twente (DIALECT) study. Adherence to oral antidiabetics (OADs), antihypertensives, and statins was determined by analyzing baseline urine samples using liquid chromatography–tandem mass spectrometry. Primary outcomes were microvascular and macrovascular complications and treatment targets of LDL cholesterol, HbA1c, and blood pressure. These were assessed cross-sectionally at baseline.RESULTS Overall, 89.3% of patients were identified as adherent. Adherence rates to OADs, antihypertensives, and statins were 95.7, 92.0, and 95.5%, respectively. The prevalence of microvascular (81.6 vs. 66.2%; P = 0.029) and macrovascular complications (55.1 vs. 37.0%; P = 0.014) was significantly higher in nonadherent patients. The percentage of patients who reached an LDL cholesterol target of ≤2.5 mmol/L was lower (67.4 vs. 81.1%; P = 0.029) in nonadherent patients. Binary logistic regression indicated that higher BMI, current smoking, elevated serum LDL cholesterol, high HbA1c, presence of diabetic kidney disease, and presence of macrovascular disease were associated with nonadherence.CONCLUSIONS Although medication adherence of real-world type 2 diabetes patients managed in specialist care was relatively high, the prevalence of microvascular and macrovascular complications was significantly higher in nonadherent patients, and treatment targets were reached less frequently. This emphasizes the importance of objective detection and tailored interventions to improve adherence.</div

Adiposity and risk of decline in glomerular filtration rate: meta-analysis of individual participant data in a global consortium

OBJECTIVE:To evaluate the associations between adiposity measures (body mass index, waist circumference, and waist-to-height ratio) with decline in glomerular filtration rate (GFR) and with all cause mortality. DESIGN:Individual participant data meta-analysis. SETTING:Cohorts from 40 countries with data collected between 1970 and 2017. PARTICIPANTS:Adults in 39 general population cohorts (n=5 459 014), of which 21 (n=594 496) had data on waist circumference; six cohorts with high cardiovascular risk (n=84 417); and 18 cohorts with chronic kidney disease (n=91 607). MAIN OUTCOME MEASURES:GFR decline (estimated GFR decline ≥40%, initiation of kidney replacement therapy or estimated GFR <10 mL/min/1.73 m2) and all cause mortality. RESULTS:Over a mean follow-up of eight years, 246 607 (5.6%) individuals in the general population cohorts had GFR decline (18 118 (0.4%) end stage kidney disease events) and 782 329 (14.7%) died. Adjusting for age, sex, race, and current smoking, the hazard ratios for GFR decline comparing body mass indices 30, 35, and 40 with body mass index 25 were 1.18 (95% confidence interval 1.09 to 1.27), 1.69 (1.51 to 1.89), and 2.02 (1.80 to 2.27), respectively. Results were similar in all subgroups of estimated GFR. Associations weakened after adjustment for additional comorbidities, with respective hazard ratios of 1.03 (0.95 to 1.11), 1.28 (1.14 to 1.44), and 1.46 (1.28 to 1.67). The association between body mass index and death was J shaped, with the lowest risk at body mass index of 25. In the cohorts with high cardiovascular risk and chronic kidney disease (mean follow-up of six and four years, respectively), risk associations between higher body mass index and GFR decline were weaker than in the general population, and the association between body mass index and death was also J shaped, with the lowest risk between body mass index 25 and 30. In all cohort types, associations between higher waist circumference and higher waist-to-height ratio with GFR decline were similar to that of body mass index; however, increased risk of death was not associated with lower waist circumference or waist-to-height ratio, as was seen with body mass index. CONCLUSIONS:Elevated body mass index, waist circumference, and waist-to-height ratio are independent risk factors for GFR decline and death in individuals who have normal or reduced levels of estimated GFR