The burden of obesity on blood pressure is reduced in older persons: the SardiNIA study.

INTRODUCTION: Being overweight or obese increases the risk of elevated blood pressure. However differences of their effects on blood pressure in different age groups are not clear. OBJECTIVE: The aim of the present study was to evaluate differences of the effects of adiposity on the odds of having hypertension in different age groups. DESIGN AND METHODS: Three thousand fifty-six subjects (1,532 women and 1,524 men) consist of the drug naïve subjects from the SardiNIA study. Logistic regression models with backward elimination were used to determine and compare the association between categories of obesity on hypertension within young (≤ 39), middle aged (40-59), and older (60+) subjects. Additional terms controlled for in the model were smoking and alcohol intake status. RESULTS: The relationship of body mass index (BMI) on hypertension differed by age, as indicated by the significant interaction term of age with BMI (P <0.01). Older subjects had higher odds of having hypertension than younger subjects but these odds were lower for obese than for lean subjects (OR 10.45, 95% CIs 4.58-23.85 in obese versus OR 33.89, 95% CIs 17.94-64.02 in lean subjects). A similar trend was also observed in middle aged subjects. CONCLUSIONS: This study shows that among men and women, older age was associated with a lesser effect of BMI on the odds of having hypertension.

24-hour intraocular pressure and blood pressure levels with latanoprost/timolol fixed combination versus timolol.

PURPOSE: To evaluate 24-hr intraocular pressure (IOP) and blood pressure (BP) with timolol or latanoprost/timolol fixed combination (LTFC). METHODS: Patients with primary open-angle glaucoma or ocular hypertension with normal blood pressure were randomized to LTFC, dosed each evening, or timolol dosed twice daily in a cross-over design for 8 weeks and the opposite medicine for 8 weeks. IOP was measured at 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 hours in the sitting position with Goldmann applanation tonometry and BP monitoring every 30 min while awake and every hour while asleep at the end of each 8-week treatment period. RESULTS: Twenty-nine patients had a 24-hr baseline IOP of 26.3 +/- 2.5 mmHg, systolic BP (SBP) of 121.4 +/- 12.4 mmHg, diastolic BP (DBP) 72.9 +/- 7.1 mmHg, and ocular perfusion pressure (OPP) of 33.9 +/- 5.7 mmHg. No statistical differences were found between untreated and treated 24-hr SBP, DBP, mean BP (MBP), heart rate, or nocturnal BP dipping status with either medication. LTFC lowered IOP more at each timepoint compared to timolol (difference between treatments 2.7 mmHg, p = 0.0002). CONCLUSIONS: Neither timolol or evening-dosed LTFC reduced SBP, DBP, MBP, OPP, or increased nocturnal dipping. LTFC was more effective than timolol in decreasing IOP.

Insulin sensitivity increase after calcium supplementation and change in intraplatelet calcium and sodium-hydrogen exchange in hypertensive patients with Type 2 diabetes.

AIMS/HYPOTHESIS: To investigate the effect of oral calcium (Ca(2+)) supplementation on insulin sensitivity measured by the euglycaemic hyperinsulinaemic clamp, intraplatelet cationic concentration of Ca(2+) ([Ca(2+)](i)) and the transmembrane sodium-hydrogen exchanger (NHE) activity in erythrocytes in subjects with Type 2 diabetes and hypertension. PATIENTS AND METHODS: In this parallel randomized controlled single-blinded trial, 31 patients were allocated to receive either 1500 mg of Ca(2+) orally, daily (n = 15) or no treatment (n = 16) for 8 weeks. At baseline and at the end of the 8-week period insulin sensitivity, [Ca(2+)](i) and the first isoform of NHE (NHE-1) activity were measured. RESULTS: At the end of the study, subjects who received Ca(2+) supplementation showed higher insulin sensitivity (Delta M-value 0.32 +/- 0.5 mmol/min P < 0.05) and lower [Ca(2+)](i) (125.0 +/- 24.7 to 80.4 +/- 10.6 nmol/l, P < 0.05, mean +/- sem) and NHE-1 activity (79.5 +/- 10.0 to 52.1 +/- 6.4 mmol Na/l red cell/h, P < 0.05). None of the above parameters were changed in the control group. Simple regression analysis demonstrated the change in [Ca(2+)](i) significantly determined insulin sensitivity change (beta = -0.36, P < 0.05). CONCLUSIONS/INTERPRETATION: Oral Ca(2+) supplementation improves insulin sensitivity in patients with Type 2 diabetes and hypertension. These changes are likely to be mediated by changes in intracellular ionic Ca(2+). NHE-1 activity was also reduced after Ca(2+) supplementation but its role in insulin sensitivity requires further investigation.

Validity and reproducibility of HOMA-IR, 1/HOMA-IR, QUICKI and McAuley's indices in patients with hypertension and type II diabetes.

The aim of this study was to evaluate the validity and reliability of homeostasis model assessment-insulin resistance (HOMA-IR) index, its reciprocal (1/HOMA-IR), quantitative insulin sensitivity check index (QUICKI) and McAuley's index in hypertensive diabetic patients. In 78 patients with hypertension and type II diabetes glucose, insulin and triglyceride levels were determined after a 12-h fast to calculate these indices, and insulin sensitivity (IS) was measured with the hyperinsulinemic euglycemic clamp technique. Two weeks later, subjects had again their glucose, insulin and triglycerides measured. Simple and multiple linear regression analysis were applied to assess the validity of these indices compared to clamp IS and coefficients of variation between the two visits were estimated to assess their reproducibility. HOMA-IR index was strongly and inversely correlated with the basic IS clamp index, the M-value (r=-0.572, P<0.001), M-value normalized with subjects' body weight or fat-free mass and every other clamp-derived index. 1/HOMA-IR and QUICKI indices were positively correlated with the M-value (r=0.342, P<0.05 and r=0.456, P<0.01, respectively) and the rest clamp indices. McAuley's index generally presented less strong correlations (r=0.317, P<0.05 with M-value). In multivariate analysis, HOMA-IR was the best fit of clamp-derived IS. Coefficients of variation between the two visits were 23.5% for HOMA-IR, 19.2% for 1/HOMA-IR, 7.8% for QUICKI and 15.1% for McAuley's index. In conclusion, HOMA-IR, 1/HOMA-IR and QUICKI are valid estimates of clamp-derived IS in patients with hypertension and type II diabetes, whereas the validity of McAuley's index needs further evaluation. QUICKI displayed better reproducibility than the other indices.