Relation between overweight, diabetes, stress and hypertension: a case-control study in Yarumal--Antioquia, Colombia.

AIMS: The aim of this study was to assess the association between overweight, diabetes, stress and other postulated risk factors for a high blood pressure, on the risk of hypertension. METHODS AND RESULTS: This matched case-control study included 228 cases randomly selected in a rural adult population in Yarumal--Antioquia, Colombia. For every case, one control, individually matched by age (+/- 5 years), sex and residence, was selected from the general population. Conditional logistic regression was used to estimate odds ratios (OR). Obese people (body mass index (BMI) > or = 30 kg/m2) showed an increased OR of hypertension compared to those with a BMI < 25 kg/m2, OR: 3.83 [95% confidence interval (CI): 1.83-8.00]. A high level of psychological stress was associated with hypertension (measured on a tension-anxiety scale), OR: 5.02 (95% CI: 2.25-11.19). A positive association was also observed for diabetes although it was of borderline significance, OR: 2.58 (95% CI: 0.88-7.55). Having a family member with hypertension or myocardial infarction was related to a higher risk of hypertension (p < 0.05). CONCLUSIONS: This study provides evidence that BMI, stress (feelings of anxiety or tension), and diabetes are independently associated with an increased risk of hypertension in a rural area of Colombia.

Differential regulation of Cdc2 and Cdk2 by RINGO and cyclins.

Cyclin-dependent kinases (Cdks) are key regulators of the eukaryotic cell division cycle. Cdk1 (Cdc2) and Cdk2 should be bound to regulatory subunits named cyclins as well as phosphorylated on a conserved Thr located in the T-loop for full enzymatic activity. Cdc2- and Cdk2-cyclin complexes can be inactivated by phosphorylation on the catalytic cleft-located Thr-14 and Tyr-15 residues or by association with inhibitory subunits such as p21(Cip1). We have recently identified a novel Cdc2 regulator named RINGO that plays an important role in the meiotic cell cycle of Xenopus oocytes. RINGO can bind and activate Cdc2 but has no sequence homology to cyclins. Here we report that, in contrast with Cdc2- cyclin complexes, the phosphorylation of Thr-161 is not required for full activation of Cdc2 by RINGO. We also show that RINGO can directly stimulate the kinase activity of Cdk2 independently of Thr-160 phosphorylation. Moreover, RINGO-bound Cdc2 and Cdk2 are both less susceptible to inhibition by p21(Cip1), whereas the Thr-14/Tyr-15 kinase Myt1 can negatively regulate the activity of Cdc2-RINGO with reduced efficiency. Our results indicate that Cdk-RINGO complexes may be active under conditions in which cyclin-bound Cdks are inhibited and can therefore play different regulatory roles.