Body composition and fat distribution influence systemic hemodynamics in the absence of obesity: the HyperGEN Study

BACKGROUND: We have shown that increased cardiac output is related to both fat-free mass and fat mass in obesity. OBJECTIVE: We studied the association of body fat distribution and body composition with flow-resistance relations in overweight. DESIGN: We studied 521 overweight, nonobese participants in the Hypertension Genetic Epidemiology Network (HyperGEN) Study-a component of the National Heart, Lung, and Blood Institute Family Blood Pressure Program, designed to assess the genetic basis of hypertension. Participants had normal ventricular function and no cardiovascular disease: 261 with central fat distribution (CFD) (waist girth >88 cm in women and >102 cm in men) and 260 with peripheral fat distribution (PFD). Fat-free mass (FFM) and fat mass (FM) were measured by bioelectric impedance. Body composition was estimated as FM/FFM. Echocardiographic stroke volume (SV) and cardiac output (CO) were measured. RESULTS: Hypertension was present in 73% of the subjects with PFD and in 78% with CFD. Overweight with CFD was associated with greater FM/FFM in both normotensive and hypertensive participants. After FFM, age, sex, and race were controlled for, SV and CO were higher in subjects overweight with CFD than in those with PFD, whereas peripheral resistance was not significantly different. Differences in CO between CFD and PFD were reduced after further adjustment for FM. After the covariates were controlled for, hypertensive subjects had higher peripheral resistance and lower arterial compliance than did normotensive participants, but cardiac output was not significantly different. CONCLUSION: CFD is associated with more severe abnormalities in body composition and with higher CO independently of FFM in overweight, nonobese subjects.     

Microanalysis of eating behavior of three leptin deficient adults treated with leptin therapy

Leptin deficiency has been associated with extreme obesity and hyperphagia in rodents and humans. A rare genetic disorder in humans yields the absence of the hormone leptin, extreme obesity, and a ravenous appetite. Reports on these rare cases have indicated that therapy using leptin injections can yield significant weight loss and changes in appetite. The aim of this report on acute leptin therapy in three leptin deficient adults was to provide a microanalysis of changes in eating behavior and ratings of hunger and satiety. In addition to substantial weight loss, 15 weeks of leptin therapy was associated with approximately 50% reduction in food intake and substantial changes in ratings of hunger and satiety before most meals. After short-term leptin therapy, the three participants ate until ratings indicated they were satiated, which was comparable to the ratings before leptin therapy. These findings suggest that one of the primary effects of acute leptin therapy may be to reduce the ravenous hunger associated with leptin deficiency, resulting in reduced food intake and significant weight loss. These results are discussed in the context of the scientific literature pertaining to leptin and its effects on appetite and obesity.     

Determinants of patient and surgeon perspectives on maximum acceptable waiting times for hip and knee arthroplasty

OBJECTIVES: Lengthy waiting times for hip and knee arthroplasty have raised concerns about equitable and timely access to care. The Western Canada Waiting List project has developed priority criteria scores linked to maximum acceptable waiting times (MAWT) for different levels of priority. Our study purpose was to assess the determinants of patient- and surgeon-rated MAWT, and to test whether the anticipated waiting time has an independent influence after adjusting for age, sex and patient urgency. A second aim was to compare MAWT, waiting time and anticipated waiting time for different levels of urgency assessed using the priority criteria score. METHODS: Orthopaedic surgeons assessed 233 consecutive patients waiting for arthroplasty in terms of their urgency (assessed using the priority criteria score and a visual analogue scale), MAWT and anticipated waiting time. Patient data included urgency (assessed by a visual analogue scale), MAWT and the Western Ontario McMaster Osteoarthritis index. We used hierarchical linear regression to test the models. RESULTS: After adjusting for age and sex, urgency (assessed by priority criteria score and visual analogue scale) and anticipated waiting time accounted for 40% of the variance in surgeon MAWT. The patient model accounted for 30% of the variance in patient MAWT. Older patients preferred signficantly shorter MAWTs (P <0.05). Anticipated waiting time added significantly to both the surgeon and patient MAWT models (R(2) change 0.11 and 0.07, respectively). Actual waiting time was weakly correlated with urgency assessed using the priority criteria score (r = -0.25, P <0.0001). CONCLUSIONS: Patients' and surgeons' views are critical to a fair process of establishing MAWT for elective procedures. Anticipated waiting time may influence the perspectives on MAWT and must be considered in their interpretation.     

Depression and fatigue in relapsing-remitting MS: the role of symptomatic variability

Depression and fatigue are common psychosocial sequelae of MS. An infrequently examined issue in the MS literature is the effect of MS-related symptom variability on incidence of depression and fatigue. The current study was designed to examine the relationship of variability in physical, cognitive, and social/environmental functioning with depression and fatigue in MS. Forty-eight relapsing-remitting MS patients from a larger sample completed self-report measures of depression and fatigue. They were also administered a structured interview that assessed current, best, and worst levels of functioning since being diagnosed with MS. Higher levels of symptom variability since disease onset were associated with depression and fatigue, even after accounting for MS-related physical disability. Regression analyses indicated that variability in social and environmental functioning was particularly associated with depression, and variability in physical abilities was associated with fatigue. These findings suggest that a more variable course of MS symptoms is associated with increased depression and fatigue. Focused assessment of variability in symptoms may be useful in detecting and subsequently treating depression and fatigue in MS patients.     

Dietary linolenic acid and adjusted QT and JT intervals in the National Heart, Lung, and Blood Institute Family Heart study

OBJECTIVES: The goal of this study was to examine whether higher consumption of total linolenic acid was associated with rate-adjusted QT and JT intervals (QTrr and JTrr, respectively). BACKGROUND: Higher intake of fish omega-3 fatty acids and plant omega-3 such as alpha-linolenic acid is associated with lower risk of myocardial infarction. While long-chain omega-3 can inhibit ventricular arrhythmia, it is not known whether alpha-linolenic acid influences ventricular repolarization. METHODS: We studied 3,642 subjects from the National Heart, Lung, and Blood Institute Family Heart study who were free of myocardial infarction, left ventricular hypertrophy, pacemaker, and with QRS <120 ms. We used the 95th percentile of the gender-specific distribution of QTrr and JTrr to define abnormally prolonged repolarization. Within each gender, we created age- and energy-adjusted tertiles of linolenic acid and used regression models for analyses. RESULTS: Mean age was 50 years, and average intake of total linolenic acid was 0.74 g/day. There was an inverse association between consumption of linolenic acid and QTrr and JTrr (p for trend 0.001 and 0.0005, respectively). From the lowest (reference) to the highest gender-, age-, and energy-adjusted tertile of linolenic acid, multivariable adjusted odds ratios for prolonged QTrr were 1.0, 0.74 (95% confidence interval [CI] 0.57 to 0.96), and 0.59 (95% CI 0.44 to 0.77), respectively (p for trend 0.0003). Corresponding values for JTrr were 1.0, 0.73 (95% CI 0.52 to 1.03), and 0.59 (95% CI 0.40 to 0.87), respectively (p for trend 0.009). Exclusion of subjects taking drugs known to influence QT did not influence this association. CONCLUSIONS: Higher intake of dietary linolenic acid might be associated with a reduced risk of abnormally prolonged repolarization in men and women.     

Left atrial systolic force and cardiac markers of preclinical disease in hypertensive patients: the Hypertension Genetic Epidemiology Network (HyperGEN) Study

BACKGROUND: Left atrial systolic force (LASF) has been recently reported to be associated with prolonged left ventricular (LV) relaxation and concentric LV geometry in a clinical setting. This study analyzes the association of increased LASF to LV geometry and function in hypertensive patients from a population study. METHODS: Doppler echocardiographic findings were examined in 684 subjects with treated hypertension and without prevalent cardiovascular disease from the Hypertension Genetic Epidemiology Network (HyperGEN) Study (426 African American, 448 female, 125 diabetic, 174 obese; age 53.8+/-10.8 years). The LASF was assessed from the mitral orifice area and pulse-wave Doppler peak A flow velocity. The LASF was defined as being high if >14.33 kdynes (90th percentile of the normal distribution in 246 normal adults). RESULTS: The LASF was high in 269 participants (39.3% of study population), who were older and had higher mean body mass index (all P<.01). Participants with high LASF had higher systolic BP and heart rate (both P<.01) but similar diastolic BP. After controlling for covariates, participants with high LASF exhibited higher LV dimensions and mass than those with normal LASF (all P<.01). The prevalence of LV hypertrophy was also higher (P<.001). Participants with high LASF exhibited normal ejection fraction, higher stroke volume, cardiac output, E and A velocities, slower E deceleration, and lower E/A ratio than those with normal LASF (all P<.01). CONCLUSIONS: Enhanced LASF is associated with LV hypertrophy, normal LV chamber function, increased cardiac output, and prolonged relaxation. The LASF is a preload-dependent measure.     

Fruit and vegetable consumption and LDL cholesterol: the National Heart, Lung, and Blood Institute Family Heart Study

BACKGROUND: An elevated LDL-cholesterol concentration is associated with an increased risk of cardiovascular disease. The association between fruit and vegetable consumption and LDL has been inconsistent. OBJECTIVE: The objective was to determine whether a high intake of fruit and vegetables is inversely associated with LDL concentrations. DESIGN: We used data collected from 4466 subjects in the National Heart, Lung, and Blood Institute Family Heart Study to study the association between fruit and vegetable consumption and serum LDL. We used a food-frequency questionnaire to assess fruit and vegetable intakes and regression models to estimate adjusted mean LDL according to fruit and vegetable consumption. RESULTS: The mean (+/-SD) age of the men (n = 2047) was 51.5 +/- 14.0 y and that of the women (n = 2419) was 52.2 +/- 13.7 y. The average daily serving of fruit and vegetables was 3.2 +/- 1.7 for men and was 3.5 +/- 1.8 for women. Fruit and vegetable consumption was inversely related to LDL: in the categories 0-1.9, 2.0-2.9, 3.0-3.9, and > or = 4 servings/d, multivariate-adjusted mean (95% CI) LDL concentrations were 3.36 (3.28, 3.44), 3.35 (3.27, 3.43), 3.26 (3.17, 3.35), and 3.17 (3.09, 3.25) mmol/L, respectively, for men (P for trend < 0.0001) and 3.35 (3.26, 3.44), 3.22 (3.14, 3.30), 3.21 (3.13, 3.29), and 3.11 (3.04, 3.18), respectively, for women (P for trend < 0.0001). This association was observed across categories of age, education, smoking status, physical activity, and tertiles of Keys score. Exclusion of subjects with prevalent diabetes mellitus or coronary artery disease did not alter these results significantly. CONCLUSION: Consumption of fruit and vegetables is inversely related to LDL in men and women.