Polymorphisms of leptin receptor (LEPR) may contribute to a common form of obesity and, as a consequence, obesity-related diseases. We evaluated the potential role of genetic variation at the LEPR gene in heart sympathetic activity and other traits related to obesity in Mexican adolescents. Adolescents aged between 12 and 17 years, with steady body weight for the last 3 months were included. We evaluated anthropometric measurements, blood pressure, seric glucose, insulin, leptin levels, heart sympathetic activity (by electrocardiograph monitoring at rest), and the Gln223Arg and Pro1019Pro LEPR polymorphisms in each subject. In total, 103 adolescents (55 obese and 48 nonobese) were included. The group of obese adolescents showed higher sympathetic activity, blood pressure, glucose, insulin, and leptin levels. The genotype frequencies for the two polymorphisms were found to be in Hardy-Weinberg equilibrium. There was no difference in the genotype frequencies for Gln223Arg or Pro1019-Pro polymorphisms between obese and nonobese adolescents. However, there was a higher prevalence of Gln223 allele among subjects with higher insulin levels (0.72 vs 0.57; P ¼ 0.04 for adolescents with insulin levels higher and lower than 100 pmol/l, respectively). According to Gln223Arg polymorphism, those with Gln allele (Gln/Gln and Gln/Arg) had higher heart sympathetic activity, body fat percentage, and leptin levels. To conclude, our results support the hypothesis that Gln223Arg polymorphism of LEPR in Mexican adolescents is associated with haemodynamic and metabolic disturbances related to obesity.

We evaluated the effectiveness of sildenafil in the treatment of neonatal pulmonary hypertension. We performed a double-blind randomized clinical trial in 51 full-term infants with persistent pulmonary hypertension confirmed by Doppler echocardiography. Patients were divided in two groups: 20 infants in group A received placebo when the oxygenation index was >20, and 31 infants in group B received 3 mg/kg of oral sildenafil every 6 hours. Arterial blood gases were taken at 1, 4, 7, 13, 19, and 25 hours after treatment was started. Main outcome measures were oxygenation changes, time on mechanical ventilation, and mortality. Both groups were comparable in general variables as well as in illness severity. We observed better oxygenation parameters after 7 hours of sildenafil treatment, but no significant changes were found in the placebo group. Mortality was higher in the placebo group (40%) than in those infants who received sildenafil (6%; P = 0.004), although no difference was found in time on mechanical ventilation between groups. Our results confirm that sildenafil may be a useful adjuvant therapy for term infants with pulmonary hypertension in centers lacking inhaled nitric oxide and extracorporeal membrane oxygenation.

No abstract

No abstract