Food: An Unrecognized Source of Loop Diuretic Resistance

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90131/1/phco.24.6.630.34736.pd

Does “Hidden Undercuffing” Occur Among Obese Patients? Effect of Arm Sizes and Other Predictors of the Difference Between Wrist and Upper Arm Blood Pressures

J Clin Hypertens (Greenwich). 2010;12:82–88. © 2009 Wiley Periodicals, Inc. Arm size can affect the accuracy of blood pressure (BP) measurement, and “undercuffing” of large upper arms is likely to be a growing problem. Therefore, the authors investigated the relationship between upper arm and wrist readings. Upper arm and wrist circumferences and BP were measured in 261 consecutive patients. Upper arm auscultation and wrist BP was measured in triplicate, rotating measurements every 30 seconds between sites. Upper arm BP was 131.9±20.6/71.6±12.6 mm Hg in an obese population (body mass index, 30.6±6.6 kg/m 2 ) with mean upper arm size of 30.7±5.1 cm. Wrist BP was higher (2.6±9.2 mm Hg and 4.9±6.6 mm Hg, respectively, P <.001); however, there was moderate concordance for the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) strata (κ value=0.27–0.71), and the difference was ≥5 mm Hg in 72% of the patients. The authors conclude that there was poor concordance between arm and wrist BP measurement and found no evidence that “hidden undercuffing” was associated with obesity; therefore, they do not support routine use of wrist BP measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78621/1/j.1751-7176.2009.00222.x.pd

Blood Pressure and Vascular Effects of Leptin in Humans

Background: Leptin may play a role in mediating obesity-related hypertension. However, its effects on the vasculature and blood pressure (BP) remain poorly defined in humans. Methods: In the first study, we performed a short-term, placebo-controlled, randomized, double-blind, cross-over experiment investigating the actions of recombinant human leptin (r-metHuLeptin) in 15 nonobese adults. To compliment the acute study, we retrospectively analyzed available BP results from a previously performed 85–day, placebo-controlled, randomized, double-blind, parallel weight-loss study using r-metHuLeptin in 284 obese adults. Results: In the acute study, conduit artery endothelial function determined by brachial flow-mediated dilatation (FMD) increased 2 hours following 0.2 mg · Kg−1 subcutaneously (SC) of r-metHuLeptin versus placebo (+3.3% versus −2.8%, P = .02). BP remained unchanged 4 hours after injections. In the retrospective analysis of the weight loss study data, 10 mg every day before noon (QAM), 10 mg every day after noon (QPM), or 10 mg twice a day (BID) SC of r-metHuLeptin was found to not alter the degree of weight loss (−3.2 ± 3.7 versus −2.9 ± 3.2 Kg, P = .54), change in systolic (−1.6 + 12.9 versus −2.0 ± 13.9 mmHg, P = .85) and diastolic BP (−0.2 ± 8.7 versus −1.5 ± 8.6, P = .30), as well as heart rate (−1.4 ± 10.7 versus −1.4 ± 10.4 beats/min, P = .98) compared to placebo. Conclusions: In our acute study, marked hyperleptinemia rapidly enhanced endothelial function and did not alter BP. The available data from a longer-term study in healthy obese adults did not demonstrate a significant effect of hyperleptinemia upon BP. These combined findings do not support a direct role for leptin in linking obesity to hypertension, however more studies are required to corroborate these observations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63121/1/met.2006.0023.pd