Obstructive sleep apnea in non-dialyzed chronic kidney disease patients: Association with body adiposity and sarcopenia.

OBJECTIVES: Obstructive sleep apnea (OSA) is a risk factor for cardiovascular disease (CVD), the main cause of mortality in chronic kidney disease (CKD). Although the prevalence of OSA in patients with CKD has not been established, a few studies suggest that it is higher than in the general population, potentially increasing the risk for CVD. Obesity increases the risk, whereas sarcopenia has been suggested as a consequence of OSA in the general population. To our knowledge, these associations have not been adequately evaluated in patients with CKD. The aim of this study was to evaluate OSA frequency and its association with total and upper body adiposity and sarcopenia in non-dialyzed CKD patients. METHODS: This cross-sectional study included 73 patients with stages 3b-4 CKD (42 men, 62.9 ± 1.1 y of age). Glomerular filtration rate was estimated by the CKD-Epidemiology Collaboration equation. Patients were assessed for OSA by Watch-PAT200 (apnea-hypopnea index ≥5 events hourly; Itamar Medical), total body adiposity by dual-energy x-ray absorptiometry (DXA) and body mass index (BMI), upper body adiposity by anthropometric parameters and by trunk and visceral fat by DXA, and sarcopenia. RESULTS: OSA frequency was 67% (N = 49). Both total and upper body adiposity were associated with the presence and severity of OSA. In non-obese patients (BMI <30 kg/m2), upper body obesity increased significantly the frequency of OSA. OSA association with sarcopenia was blunted when BMI was included in regression model. CONCLUSIONS: Results from the present study suggest that in non-dialyzed CKD patients OSA is very common and associated with total and upper body obesity, but not with sarcopenia.

Serum Uric Acid Levels are Associated with Cardiometabolic Risk Factors in Healthy Young and Middle-Aged Adults / Os Níveis Séricos de Ácido Úrico estão Associados a Fatores de Risco Cardiometabólico em Adultos Jovens e de Meia-Idade Saudáveis

Abstract Background: Observational studies have highlighted an association between serum uric acid (SUA) levels and cardiovascular risk factors. Despite the growing body of evidences, several studies were conducted in older individuals or in carriers of diseases susceptible to affect SUA levels and cardiometabolic risk markers. Objective: To evaluate the relationship of SUA with body adiposity, metabolic profile, oxidative stress, inflammatory biomarkers, blood pressure and endothelial function in healthy young and middle-aged adults. Methods: 149 Brazilian adults aged 20-55 years, both sexes, underwent evaluation of body adiposity, SUA, fasting glucose and insulin, lipid profile, malondialdehyde (MDA), high sensitivity C-reactive protein (hs-CRP), adiponectin, blood pressure and endothelial function. Endothelial function was assessed by the reactive hyperemia index (RHI) derived from peripheral arterial tonometry method. Participants were allocated in two groups according to SUA levels: control group (CG; n = 130; men ≤ 7 mg/dL, women ≤ 6 mg/dL) and hyperuricemia group (HG; n = 19; men > 7 mg/dL, women > 6 mg/dL). A P-value < 0.05 was considered statistically significant. Results: After adjustment for confounders, participants in HG compared with those in CG displayed higher body mass index (BMI): 34.15(33.36-37.19) vs.31.80 (26.26-34.42) kg/m2,p = 0.008, higher MDA: 4.67(4.03-5.30) vs. 3.53(3.10-4.07) ng/mL, p < 0.0001 and lower RHI: 1.68 ± 0.30 vs. 2.05 ± 0.46, p = 0.03). In correlation analysis adjusted for confounders, SUA was positively associated (p < 0.05) with BMI, waist circumference, LDL-cholesterol, triglycerides and MDA, and negatively associated (p < 0.05) with HDL-cholesterol, adiponectin and RHI. Conclusions: This study suggests that in healthy young and middle-aged adults higher SUA levels are associated with higher body adiposity, unfavorable lipid and inflammatory phenotype, higher oxidative stress and impaired endothelial function.

Resumo Fundamento: Estudos observacionais têm destacado uma associação entre níveis de ácido úrico sérico (AUS) e fatores de risco cardiovascular. Apesar do crescente conjunto de evidências, vários estudos foram realizados em indivíduos mais velhos ou em portadores de doenças passíveis de influenciar os níveis de AUS e marcadores de risco cardiometabólico. Objetivo: Avaliar a relação do AUS com adiposidade corporal, perfil metabólico, estresse oxidativo, biomarcadores de inflamação, pressão arterial e função endotelial em adultos jovens e de meia-idade saudáveis. Métodos: 149 adultos, brasileiros, com idades entre 20 e 55 anos, de ambos os sexos, foram submetidos a avaliação de adiposidade corporal, AUS, glicose e insulina de jejum, perfil lipídico, malondialdeído (MDA), proteína C-reativa ultra-sensível (PCR-us), adiponectina, pressão arterial e função endotelial. A função endotelial foi avaliada pelo índice de hiperemia reativa (RHI) derivado do método de tonometria arterial periférica. Os participantes foram divididos em dois grupos de acordo com os níveis de AUS: grupo de controle (GC; n = 130; homens ≤ 7 mg/dL, mulheres ≤ 6mg/dL) e grupo de hiperuricemia (GH; n = 19; homens > 7mg/dL, mulheres > 6mg/dL). Valor de p < 0,05 foi considerado estatisticamente significativo. Resultados: Após ajuste para fatores de confundimento, os participantes do GH comparados aos do GC apresentaram índice de massa corporal (IMC) mais alto: 34,15 (33,36-37,19) vs. 31,80 (26,26-34,42) kg/m2, p = 0,008, MDA mais alto: 4,67(4,03-5,30) vs. 3,53(3,10-4,07) ng/mL, p < 0,0001 e RHI mais baixo: 1,68 ± 0,30 vs. 2,05 ± 0,46, p = 0,03. Na análise de correlação ajustada para fatores de confundimento, o AUS se associou positivamente (p < 0,05) com IMC, circunferência da cintura, LDL colesterol, triglicérides e MDA, e se associou negativamente (p < 0,05) com HDL colesterol, adiponectina e RHI. Conclusões: Este estudo sugere que, em adultos jovens e de meia-idade saudáveis, níveis mais altos de AUS estão associados a maior adiposidade corporal, fenótipo inflamatório e de lipídios desfavorável, maior estresse oxidativo e função endotelial comprometida.

Serum Uric Acid Levels are Associated with Cardiometabolic Risk Factors in Healthy Young and Middle-Aged Adults.

BACKGROUND: Observational studies have highlighted an association between serum uric acid (SUA) levels and cardiovascular risk factors. Despite the growing body of evidences, several studies were conducted in older individuals or in carriers of diseases susceptible to affect SUA levels and cardiometabolic risk markers. OBJECTIVE: To evaluate the relationship of SUA with body adiposity, metabolic profile, oxidative stress, inflammatory biomarkers, blood pressure and endothelial function in healthy young and middle-aged adults. METHODS: 149 Brazilian adults aged 20-55 years, both sexes, underwent evaluation of body adiposity, SUA, fasting glucose and insulin, lipid profile, malondialdehyde (MDA), high sensitivity C-reactive protein (hs-CRP), adiponectin, blood pressure and endothelial function. Endothelial function was assessed by the reactive hyperemia index (RHI) derived from peripheral arterial tonometry method. Participants were allocated in two groups according to SUA levels: control group (CG; n = 130; men ≤ 7 mg/dL, women ≤ 6 mg/dL) and hyperuricemia group (HG; n = 19; men > 7 mg/dL, women > 6 mg/dL). A P-value < 0.05 was considered statistically significant. RESULTS: After adjustment for confounders, participants in HG compared with those in CG displayed higher body mass index (BMI): 34.15(33.36-37.19) vs.31.80 (26.26-34.42) kg/m2,p = 0.008, higher MDA: 4.67(4.03-5.30) vs. 3.53(3.10-4.07) ng/mL, p < 0.0001 and lower RHI: 1.68 ± 0.30 vs. 2.05 ± 0.46, p = 0.03). In correlation analysis adjusted for confounders, SUA was positively associated (p < 0.05) with BMI, waist circumference, LDL-cholesterol, triglycerides and MDA, and negatively associated (p < 0.05) with HDL-cholesterol, adiponectin and RHI. CONCLUSIONS: This study suggests that in healthy young and middle-aged adults higher SUA levels are associated with higher body adiposity, unfavorable lipid and inflammatory phenotype, higher oxidative stress and impaired endothelial function.

The effects of moderate energy restriction on apnoea severity and CVD risk factors in obese patients with obstructive sleep apnoea.

Nutritional intervention for weight loss is one of the treatment options for obstructive sleep apnoea (OSA) in patients with overweight or obesity. However, the effects of moderate energy restriction on OSA severity are not yet known. The present study aimed to evaluate the effects of moderate energy restriction on OSA severity and CVD risk factors in obese patients with OSA. In this 16-week randomised clinical trial, twenty-one obese subjects aged 20-55 years and presenting an apnoea/hypopnoea index (AHI)≥5 events/h were randomised into two groups: the energy restriction group (ERG) and the control group (CG). The ERG was instructed to follow an energy-restricted diet -3347·2 kJ/d (-800 kcal/d) and the CG was advised not to change their food intake. At the beginning and at the end of the study, participants underwent evaluation of the following: OSA (Watch-PAT200®), nutritional parameters, blood pressure, sympathetic activity, inflammatory biomarkers, metabolic profile and endothelial function. The ERG (n 11), compared with the CG (n 10), had a significantly greater reduction in body weight (Cohen's d=-1·19; P<0·001), in AHI (Cohen's d=-0·95; P=0·04) and in plasma concentrations of adrenaline (Cohen's d=-1·02; P=0·04) as well as a significantly greater increase in minimum O2 saturation (Cohen's d=1·08; P=0·03). Although energy restriction was not associated with significant improvements in CVD risk factors, medium-to-large effect sizes were observed, suggesting that the statistically non-significant difference between groups may be due to the small sample size. This study suggests that in obese patients with OSA, moderate energy restriction is able to reduce the parameters of OSA severity and sympathetic activity.

Obstructive sleep apnea is independently associated with inflammation and insulin resistance, but not with blood pressure, plasma catecholamines, and endothelial function in obese subjects.

OBJECTIVES: Obstructive sleep apnea (OSA) is associated with an increased risk of cardiovascular disease (CVD). Several of the proposed mechanisms for the development of CVD in OSA are similar to those proposed for the increased risk of CVD in obesity, so that it is difficult to determine the influence of OSA on these pathogenic mechanisms in obese individuals. The aim of this study was to evaluate the relationship of OSA with endothelial function, oxidative stress, inflammatory biomarkers, metabolic profile, sympathetic nervous system activity, and blood pressure (BP) in obese individuals. METHODS: This cross-sectional study included 53 obese adults (28 women). Sleep study was performed with WatchPAT 200 (Itamar Medical, Caesarea, Israel) and the diagnosis of OSA was made when apnea-hypopnea index (AHI) ≥5 events/h (n = 33). All participants underwent evaluation of: body adiposity, BP, plasma catecholamines, high sensitivity C-reactive protein (hs-CRP), adiponectin, malondialdehyde, glucose, insulin, lipid profile, and endothelial function (EndoPAT 2000). RESULTS: In univariate analysis, participants with OSA compared with those without OSA exhibited higher values of neck circumference, glucose, noradrenaline, and systolic BP. After adjustment for confounders, including adiposity, only glucose and hs-CRP were significantly higher in OSA patients. In correlation analysis, after controlling for confounders, AHI was positively and significantly associated with neck circumference and hs-CRP, while minimum O2 saturation was associated negatively and significantly with neck circumference, insulin and homeostatic model assessment-insulin resistance (HOMA-IR). CONCLUSIONS: The present study suggests that in obese individuals OSA is independently associated with inflammation and insulin resistance, but not with BP, plasma catecholamines and endothelial function.

Adiposity and cardiovascular disease risk factors in renal transplant recipients: Are there differences between sexes?

OBJECTIVE: The aim of this study was to evaluate high body adiposity and cardiovascular disease (CVD) risk factors prevalence, in renal transplant recipients (RTR), comparing men with women. METHODS: In this retrospective cross-sectional study, 102 patients (55 men) who were 49 ± 1.2 y and 114.3 ± 9 mo post-transplant (post-tx) were evaluated. Pretransplant (pre-tx) period data and weight gain during the first year post-tx were obtained from patient charts and post-tx data were collected during a routine visit at nephrology clinic. Body mass index (BMI) ≥ 25 kg/m(2) defined overweight and BMI ≥ 30 kg/m(2) defined obesity. RESULTS: Pre-tx overweight prevalence was low and similar between men and women (26%), whereas only women showed obesity (11%). Post-tx body weight increased significantly in the entire group, leading to an increase in overweight (to 38% in men and 51% in women) and obesity (to 11% in men and 23% in women) prevalence. Post-tx comparisons between men and women showed that women had higher (women versus men; P < 0.05) BMI values (26.7 ± 0.8 versus 24.7 ± 0.5 kg/m(2)), weight gain during first year post-tx (9.2 ± 1.1 versus 5.5 ± 1 kg), abdominal obesity (57% versus 23%) and diabetes (34% versus 16%) prevalence. The associations between adiposity and CVD risk factors showed that pre-tx overweight increased the risk for diabetes in post-tx; pos-tx high BMI and abdominal obesity increased the risk for metabolic syndrome; abdominal obesity increased the risk for dyslipidemia in women. CONCLUSIONS: High body adiposity prevalence was high after transplantation and increased the risk for metabolic syndrome, an important CVD risk factor. Women showed higher total body adiposity values, abdominal obesity, and diabetes prevalence than men. Abdominal obesity increased the risk for dyslipidemia in women.