## 2 Materials and Methods  
### Study Design and Procedures  
The current study, which is based on data collected between 2014 and 2016, forms part of the ongoing Vascular and Metabolic Health (VMH) study, an extension of the Cape Town Bellville South study, previously described in detail [26]. Ethical clearance for the VMH study was granted by the research ethics committees of the Cape Peninsula University of Technology (CPUT) and Stellenbosch University (NHREC: REC--230, 408-014,and N14/01/003, respectively). For the current study, ethical clearance was granted by the Faculty of Health and Wellness Sciences Research Ethics Committee of the CPUT (CPUT/HW-REC 2020/H11). The participants gave signed and written consent after they were informed about their rights and the procedures were fully explained in the language of their choice. Research was carried out in accordance with the Code of Ethics of the World Medical Association (Declaration of Helsinki). A total of 1989 individuals of mixed-ancestry were recruited between 2014 and 2016 as part of the VMH Study and of these 911 individuals had HTN and DM, with age range between 20 and 91, a median age of 56 years and were thus selected for the present analysis (18.8% with CKD and 22 % males). Of the total sample 6.4%, 3.6%, 7.1%, 1.2% and 0.4% of the individuals were in CKD stages 1-5 respectively. The detailed data collection procedures, using standardized questionnaires and physical examination, were explained elsewhere [25]. Briefly, clinical measurements, including body weight, height, hip circumference (HC), waist circumference (WC), and blood pressure (BP), were taken by trained personnel via standardized methods. Body mass index (BMI) was calculated as weight in kilograms divided by the square of height in meters (kg/m\({}^{2}\)). Participants were classified as underweight (BMI \(<\) 18.5 kg/m\({}^{2}\)), normal weight (BMI 18.5-4.9 kg/m\({}^{2}\)), overweight (BMI 25.0-29.99 kg/m\({}^{2}\)), and obese (BMI \(\geq\) 30.0 kg/m\({}^{2}\)). BP measurements were performed according to WHO guidelines [27], using an automatic digital BP monitor (Omron M6 Comfort-preformed Cuff Blood Pressure Monitor, Omron), with the participants sitting quietly in a relaxed position for at least 5 min. Two BP readings, including systolic BP (SBP) and diastolic BP (DBP), at three-minute intervals, were taken and the lowest SBP and the corresponding DBP were chosen as the participant's BP. Pulse pressure (PP) was estimated by subtracting the DBP from the SBP. HTN was defined as SBP \(\geq\) 140 mmHg and/or DBP \(\geq\) 90 mmHg or self-reported ongoing use of antihypertensive medications. All biochemical analysis was conducted by an ISO accredited pathology practice (PathCare Laboratory, Cape Town, South Africa). All participants, excluding those who self-reported diabetes mellitus (confirmed by either participant medical card record or use of diabetic medication), underwent a 75 g oral glucose tolerance test (OGTT) after an overnight fast, according to WHO guidelines [28]. DM was defined as a fasting blood glucose (FBG) of \(\geq\)7.0 mmol/L and/or a 2 h postprandial glucose (Glucose 2 HR) of \(\geq\)11.1 mmol/L, or ongoing use of glucose control medications. Plasma glucose concentrations were measured using the enzymatic hexokinase method (Beckman AU, Beckman Coulter, Brea, CA, USA), glycated hemoglobin (HbA1c) was measured using high performance liquid chromatography (HPLC) (Biorad Variant Turbo, BioRad, Hercules, CA, USA), urine albumin levels were measured using the colorimetric (bromosced purple) method (Beckman AU, Beckman Coulter, Brea, CA, USA), and serum and urinary creatinine was measured by the modified Jaffe kinetic method (Beckman AU, Beckman Coulter, Brea, CA, USA).