Intensive Lifestyle Intervention Increases Plasma Midregional Proatrial Natriuretic Peptide Concentrations in Overweight Children.

Background Overweight adults have low circulating concentrations of ANP (atrial natriuretic peptide) and proANP fragments. We tested the hypothesis that an intensive lifestyle intervention with an intended weight loss would increase plasma concentrations of a proANP fragment in overweight children. Methods and Results We measured MR-proANP (midregional proANP) concentrations in plasma from overweight children who participated in the OOIS (Odense Overweight Intervention Study). OOIS randomized 115 overweight children (11-13 years, 55% girls) to an intensive day-camp intervention arm with increased physical activity and healthy diet or to a less intensive standard intervention arm for 6 weeks. We used linear mixed-effects modeling for repeated measures to estimate the difference in the mean change with 95% CIs in fasting plasma MR-proANP concentrations between the 2 arms, and we used partial least squares regression analysis to identify candidate mediators. Differences in weight, fitness, and metabolic factors were also analyzed. At baseline, fasting plasma MR-proANP concentrations were (median [interquartile range]) 35.0 pmol/L (26.8-42.0) in the day-camp intervention arm and 37.2 pmol/L (31.7-44.7) in standard intervention arm participants, respectively. After 6 weeks intervention, children in the day-camp intervention arm had increased their MR-proANP (5.4 pmol/L [0.8-10.0], P=0.022) and their fitness (2.33 mL O2/min per kg [0.52-4.14], P=0.012) and they had deceased their body mass index (-2.12 kg/m2 [-2.59 to -1.65], P<0.001) as compared with children in standard intervention arm. In the partial least squares analysis, decreases in fasting insulin and in estimated insulin resistance were associated with the observed increase in MR-proANP concentrations. Conclusions An intensive lifestyle intervention increases plasma MR-proANP among overweight children. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01574352.

Plasma proatrial natriuretic peptide associates with lipid oxidation during exercise and cardiorespiratory fitness in healthy young adults.

Atrial natriuretic peptide (ANP) is known for its natriuretic, diuretic, and vasodilatory properties. However, ANP also has metabolic effects stimulating lipolysis and lipid oxidation. Overweight individuals have decreased circulating ANP concentrations. It has been proposed that this potential ANP deficiency could have biological consequences in overweight-related disorders, including decreased lipolysis and lipid oxidation. The purpose of this study was to investigate the relationships between ANP, exercise-induced lipid oxidation, and cardiorespiratory fitness in 562 20-28-year-old healthy community-based women and men. We measured fasting plasma concentrations of mid-regional proANP (MR-proANP), a stable marker of ANP secretion, the respiratory exchange ratio (RER) during sub-maximal exercise, which provides an estimate of lipid oxidation, and maximal oxygen consumption (VO2-max) at the end of a maximal exercise test, which is a measure of cardiorespiratory fitness. An increase of 10 pmol/L in fasting plasma MR-proANP concentrations was related to an increase in relative VO2-max of 0.78 (95% CI 0.36-1.09) ml O2/min/kg and a decrease in RER of -0.0094 (-0.014 to -0.0045) in age- and sex-adjusted analysis (P < 0.001). Further adjusted for body mass index, a rise of 10 pmol/L in fasting plasma MR-proANP concentrations was associated with a rise in relative VO2-max of 0.60 (0.28-0.92) ml O2/min/kg and a fall in RER of -0.0096 (-0.015 to -0.0048) (P < 0.001). Fasting plasma MR-proANP concentrations associate with lipid oxidation during exercise and cardiorespiratory fitness in healthy young adults. The data support the existence of important connections between the endocrine heart, hemodynamics, and metabolism.

Association of copeptin, a surrogate marker for arginine vasopressin secretion, with insulin resistance: Influence of adolescence and psychological stress.

In middle-aged and elderly individuals, circulating copeptin concentrations, a surrogate marker for arginine vasopressin (AVP) secretion, associates with insulin resistance (IR). Whether this association is present in adolescents and young adults is unclear. Because psychological stress associates with higher circulating copeptin concentrations and IR, it has been speculated that increased AVP secretion could be a link between psychological stress and IR. We measured plasma copeptin concentrations in 351 14-16-year-old adolescents and 617 20-28-year-old young adults from the Danish site of the European Youth Heart Study, a population-based cardiovascular risk factor study in adolescents and young adults. IR was determined by the homeostatic model assessment method. Among the young adults, we used symptoms of depression, evaluated by means of the Major Depression Inventory (MDI) scale, as a measure of psychological stress. We applied linear regressions to examine associations, expressed as unstandardized regression coefficients (B) with 95% confidence intervals (CIs), between variables of interest, stratified by age group and adjusting for age, sex and Tanner stages. Copeptin and IR were log-transformed. Among the young adults, copeptin associated with IR (B (95%CI) = 0.19 (0.11 to 0.27), P < 0.001). This association was not found among the adolescents (B=-0.01 (-0.12 to 0.09), P = 0.78). MDI score associated with IR (B = 0.010 (0.004 to 0.016), P < 0.001) and copeptin (B=0.010 (0.004 to 0.015); P<0.002) in the young adults. Adjusted for copeptin, the strength of the association between MDI score and IR somewhat diminished (to B=0.008). In conclusion, adolescence and psychological stress appear to influence the association between copeptin and IR.

Coronary computed tomography angiography - tolerability of ß-blockers and contrast media, and temporal changes in radiation dose.

OBJECTIVE: To determine the risk in administering ß-blockers, contrast-induced nephropathy (CIN) and the trend in X-ray use, during coronary computed tomography angiography (CCTA). METHODS: A total of 416 patients were referred for elective CCTA. To achieve a resting heart rate below 60 beats per minute, oral and/or intravenous ß-blockers were administered. Using questionnaires, information on the adverse effects of ß-blockers was collected from the patients. The levels of s-creatinine and estimated GFR (eGFR) were measured before and after contrast enhanced CCTA. Radiation exposure was compared with the exposure 3 years earlier. RESULTS: There was no significant difference in the symptoms (dizziness, lipothymia and palpitations) between patients with and patients without ß-blocker pretreatment. Compared to baseline values, the decrease in s-creatinine was not significant (75.2 vs. 74.6 µmol/L, p = 0.09), while the increase in eGFR was not significant (78 vs. 79 mL/min, p = 0.17). Also, subgroups of patients with hypertension, hypercholesterolemia, diabetes or pre-existing slight impairment in renal function did not develop CIN. The mean radiation exposure decreased from 17.5 to 6.7 mSv, p < 0.0001. CONCLUSIONS: In terms of the side effects of ß-blockers and contrast media, there were no short term complications to CCTA. Furthermore, the radiation dose has been dramatically diminished over the last three years.