Short-Term Effects of Weight Loss on Microvascular Reactivity and Central Pressure in Adults with Obesity Attenuated by Moderate to Severe Obstructive Sleep Apnea

Background and Objective Obstructive sleep apnea (OSA) has been considered a risk factor for cardiovascular diseases. This study evaluated whether moderate or severe OSA attenuates the vascular benefits of weight loss induced by a short-term nutritional intervention in individuals with obesity. Methods Prospective 8-week energy restriction (-800Kcal/day) study included individuals aged 40–70 years with body mass index 30–40 kg/m 2 . Microvascular reactivity, heart rate variability, and central hemodynamics by oscillometry were evaluated at baseline and after 8 weeks. The sleep study was performed through a portable home device (WatchPAT-200). Results Patients ( n = 76) were divided according to apnea-hypopnea-index in absent-mild (AM) OSA group (< 15events/h, n = 30) and moderate-severe (MS) OSA group (≥ 15events/h, n = 46). At the end of the study both groups showed similar weight loss (3.2 ± 2.3 vs. 3.0 ± 2.7%, p = 0.898). Only AM group showed a significant increase in the RR interval (879 ± 118 vs. 948 ± 130 ms, p = 0.016) and in cutaneous vascular conductance post-occlusive reactive hyperemia (1.17 ± 0.23 vs. 1.27 ± 0.20 APU/mmHg, p = 0.033), decrease in central systolic pressure (113 ± 12 vs. 107 ± 9 mmHg, p = 0.006) and in pulse wave velocity (PWV, 6.9 ± 0.6 vs. 6.7 ± 0.6 m/s, p = 0.004). Conclusions After short term of nutritional intervention, individuals with obesity had modest weight loss regardless of OSA severity but vascular outcomes were improved primarily in the absence of moderate or severe OSA.