Obesity and risk for hypertension and diabetes among Kenyan adults: Results from a national survey.

ABSTRACT: Despite the anticipated growth in the global burden of obesity especially in low-income countries, limited data exist on the contribution of obesity to cardiometabolic diseases in Africa.We examined population-based samples of Kenyan adults who participated in the 2015 national chronic disease risk factor surveillance survey. Weight and height were measured, and body mass index (BMI) was calculated and used as a measure for general obesity. Waist circumference (WC), a clinical measure of central obesity was also measured. Logistic regression was used to assess the association between obesity with hypertension, diabetes, and dyslipidemia risk.Of the 4276 participants, the median (IQR) age was 36 (27-47) years, 41% were men. One-third (37%) of the participants were centrally obese, whereas 10% were generally obese. The odds for overweight and general obesity were highest among females, adults >40 years, and those in the highest wealth quartile. Central and general obesity, assessed by WC and BMI, were associated with hypertension and dyslipidemia but not diabetes for both sexes. Compared with adults of normal weight, individuals with a BMI of ≥30 kg/m2 had an odds ratio of 2.39 (95% confidence interval [CI], 1.82-3.12) for hypertension and 2.24 (95% CI, 1.70-2.96) for dyslipidemia.Obesity prevalence is high in Kenya and is associated with hypertension and dyslipidemia but not diabetes. Our findings indicate an urgent need to develop public health interventions to address obesity and prevent the development of comorbid conditions.

Glomerular endothelial cell maturation depends on ADAM10, a key regulator of Notch signaling.

The principal function of glomeruli is to filter blood through a highly specialized filtration barrier consisting of a fenestrated endothelium, the glomerular basement membrane and podocyte foot processes. Previous studies have uncovered a crucial role of endothelial a disintegrin and metalloprotease 10 (ADAM10) and Notch signaling in the development of glomeruli, yet the resulting defects have not been further characterized nor understood in the context of kidney development. Here, we used several different experimental approaches to analyze the kidneys and glomeruli from mice lacking ADAM10 in endothelial cells (A10ΔEC mice). Scanning electron microscopy of glomerular casts demonstrated enlarged vascular diameter and increased intussusceptive events in A10ΔEC glomeruli compared to controls. Consistent with these findings, genes known to regulate vessel caliber (Apln, AplnR and Vegfr3) are significantly upregulated in A10ΔEC glomeruli. Moreover, transmission electron microscopy revealed the persistence of diaphragms in the fenestrae of A10ΔEC glomerular endothelial cells, which was corroborated by the elevated expression of the protein PLVAP/PV-1, an integral component of fenestral diaphragms. Analysis of gross renal vasculature by light sheet microscopy showed no major alteration of the branching pattern, indicating a localized importance of ADAM10 in the glomerular endothelium. Since intussusceptions and fenestrae with diaphragms are normally found in developing, but not mature glomeruli, our results provide the first evidence for a crucial role of endothelial ADAM10, a key regulator of Notch signaling, in promoting the development and maturation of the glomerular vasculature.

Pbx1-dependent control of VMC differentiation kinetics underlies gross renal vascular patterning.

The architecture of an organ's vascular bed subserves its physiological function and metabolic demands. However, the mechanisms underlying gross vascular patterning remain elusive. Using intravital dye labeling and 3D imaging, we discovered that systems-level vascular patterning in the kidney is dependent on the kinetics of vascular mural cell (VMC) differentiation. Conditional ablation of the TALE transcription factor Pbx1 in renal VMC progenitors in the mouse led to the premature upregulation of PDGFRß, a master initiator of VMC-blood vessel association. This precocious VMC differentiation resulted in nonproductive angiogenesis, abnormal renal arterial tree patterning and neonatal death consistent with kidney dysfunction. Notably, we establish that Pbx1 directly represses Pdgfrb, and demonstrate that decreased Pdgfrb dosage in conditional Pbx1 mutants substantially rescues vascular patterning defects and neonatal survival. These findings identify, for the first time, an in vivo transcriptional regulator of PDGFRß, and reveal a previously unappreciated role for VMCs in systems-level vascular patterning.