Israel Medical Association Journal

Background: Multiple factors are involved in the pathogenesis of hypertension in the obese individual.

Objective: To evaluate the role of a decrease in sympathetically mediated thermogenesis and the effect of the correlation between the plasma leptin and daily urinary nitric oxide levels on obesity-related hypertension.

Methods: We evaluated three groups: 25 obese hypertensive patients (age 45.7±1.37 years, body mass index 34.2±1.35 kg/m², systolic/diastolic blood pressure 155±2.9/105±1.3, mean arterial pressure 122±1.50 mmHg); 21 obese normotensive patients (age 39.6±1.72, BMI[1] 31.3±0.76, SBP/DBP[2] 124±2.1/85.4±1.8, MAP[3] 98.2±1.80); and 17 lean normotensive subjects (age 38.1±2.16, BMI 22.1±0.28, SBP/DBP 117±1.7/76.8±1.5, MAP 90.1±1.50). We determined basal resting metabolic rates, plasma insulin (radioimmunoassay), norepinephrine (high performance liquid chromatography) in all subjects. Thereafter, 14 obese hypertensives underwent a weight reduction diet. At weeks 6 (n=14) and 14 (n=10) of the diet the above determinations were repeated. Plasma leptin (enzyme-linked immunosorbent assay) and UNOx[4] (spectrophotometry) were assayed in 17 obese hypertensives and 17 obese normotensives, and in 19 obese hypertensives versus 11 obese normotensives, respectively.

Results: Obese hypertensive patients had significantly higher basal RMR[5] and plasma NE[6] levels. Insulin levels were lower in the lean group, with no difference between the hypertensive and normotensive obese groups. At weeks 6 and 14, BMI was significantly lower, as were insulin and NE levels. RMR decreased to values of normotensive subjects. MAP normalized but remained significantly higher than that of obese normotensives. Leptin blood levels and the leptin/UNOx ratio were significantly higher in the obese hypertensive compared to the obese normotensive patients. Both these parameters were strongly correlated to BMI, MAP⁵, RMR, and plasma NE and insulin .Obese hypertensive patients excreted less urinary NO metabolites. A strong correlation was found between MAP and the leptin/UNOx ratio.  

Conclusions: A reduction of sympathetically mediated thermogenesis, as reflected by RMR, results in normalization of obesity-related hypertension. In contrast, insulin does not seem to play a major role in the pathogenesis of hypertension associated with obesity. Increased leptin levels in conjunction with decreased NO production in the presence of enhanced sympathetic activity may contribute to blood pressure elevation in the obese.

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[1] BMI = body mass index

[2] SBP/DBP = systolic blood pressure/diastolic blood pressure

[3] MAP = mean arterial pressure

[4] UNOx = urinary nitric oxide

[5] RMR – resting metabolic rate

[6] NE = norepinephrine

Background: Erysipelas is a skin infection generally caused by group A streptococci. Although penicillin is the drug of choice, some physicians tend to treat erysipelas with antibiotics other than penicillin.

Objectives: To define the pattern of antibiotic use, factors affecting antibiotic selection, and outcome of patients treated with penicillin versus those treated with other antimicrobial agents.

Methods: A retrospective review of charts of adult patients with discharge diagnosis of erysipelas was conducted for the years 1993-1996.

Results: The study group comprised 365 patients (median age 67 years). In 76% of the cases infection involved the leg/s. Predisposing condition/s were present in 82% of cases. Microorganisms were isolated from blood cultures in only 6 of 176 cases (3%), and Streptococcus spp. was recovered in four of these six patients. Cultures from skin specimens were positive in 3 of 23 cases. Penicillin alone was given to 164 patients (45%). Other antibiotics were more commonly used in the second half of the study period (P < 0.0001) in patients with underlying conditions (P = 0.06) and in those hospitalized in the dermatology ward (P< 0.0001). Hospitalization was significantly shorter in the penicillin group (P= 0.004). There were no in-hospital deaths.

Conclusions: We found no advantage in using antibiotics other than penicillin for treating erysipelas. The low yield of skin and blood cultures and their marginal impact on manage­ment, as well as the excellent outcome suggest that this infection can probably be treated empirically on an outpatient basis.