Cardiorespiratory Fitness, Alcohol Intake, and Metabolic Syndrome Incidence in Men

Purpose To prospectively examine the independent and joint effects of alcohol consumption and cardiorespiratory fitness on the incidence of metabolic syndrome in a cohort of men. Methods A prospective examination of 3,411 apparently healthy men at baseline, who came to the Cooper Clinic (Dallas, Texas) for at least 2 preventive visits (1979–2010). Primary exposure variables were cardiorespiratory fitness and alcohol intake; the outcome measure was metabolic syndrome (MetS) and the components thereof. Cox proportional hazard models were computed to assess the relationship between the exposure variables and the incidence of MetS while adjusting for confounders. Results Over a mean follow-up period of 9 years (SD=7.8), 276 men developed MetS. In multivariable analysis, a dose-response relationship was observed between increased levels of fitness and reduced MetS risk (moderate fitness: HR=0.60, 95%CI 0.43–0.82; high fitness: HR=0.49, 95%CI 0.35–0.69). When examining the independent effects of alcohol, light drinking increased the risk for MetS by 66% (HR=1.66, 95%CI 1.11–2.48). No statistically significant interaction effect was observed between alcohol and fitness in relation to MetS (P = 0.32). When assessing the relation between each exposure and the components of MetS, higher fitness consistently reduced the risk of all components; whereas lower alcohol intake reduced the risk of elevated glucose and blood pressure and increased the risk for low HDL-c. Conclusions Among this cohort of men, higher fitness levels reduced the risk for MetS and its components. The relation between alcohol intake levels and metabolic risk was more complex and not reflected when examining MetS as a whole

Associations Between Cardiorespiratory Fitness and C-Reactive Protein in Men

Objective - This study examined the association between cardiorespiratory fitness and C-reactive protein (CRP), with adjustment for weight and within weight categories. Methods and Results - We calculated median and adjusted geometric mean CRP levels, percentages of individuals with an elevated CRP (≥2.00 mg/L), and odds ratios of elevated CRP across 5 levels of cardiorespiratory fitness for 722 men. CRP values were adjusted for age, body mass index, vitamin use, statin medication use, aspirin use, the presence of inflammatory disease, cardiovascular disease, and diabetes, and smoking habit. We found an inverse association of CRP across fitness levels (P for trend\u3c0.001), with the highest adjusted CRP value in the lowest fitness quintile (1.64 [1.27 to 2.11] mg/L) and the lowest adjusted CRP value in the highest fitness quintile (0.70 [0.60 to 0.80] mg/L). Similar results were found for the prevalence of elevated CRP across fitness quintiles. We used logistic regression to model the adjusted odds for elevated CRP and found that compared with the referent first quintile, the second (odds ratio [OR] 0.43, 95% CI 0.22 to 0.85), third (OR 0.33, 95% CI 0.17 to 0.65), fourth (OR 0.23, 95% CI 0.12 to 0.47), and fifth (OR 0.17, 95% CI 0.08 to 0.37) quintiles of fitness had significantly lower odds of elevated CRP. Similar results were found when examining the CRP-fitness relation within categories of body fatness (normal weight, overweight, and obese) and waist girth (\u3c102 or ≥102 cm). Conclusions - Cardiorespiratory fitness levels were inversely associated with CRP values and the prevalence of elevated CRP values in this sample of men from the Aerobics Center Longitudinal Study

Lifetime Risks for Cardiovascular Disease Mortality by Cardiorespiratory Fitness Levels Measured at Ages 45, 55, and 65 Years in Men The Cooper Center Longitudinal Study

ObjectivesThe purpose of this study was to determine the association between fitness and lifetime risk for cardiovascular disease (CVD).BackgroundHigher levels of traditional risk factors are associated with marked differences in lifetime risks for CVD. However, data are sparse regarding the association between fitness and the lifetime risk for CVD.MethodsWe followed up 11,049 men who underwent clinical examination at the Cooper Institute in Dallas, Texas, before 1990 until the occurrence of CVD death, non-CVD death, or attainment of age 90 years (281,469 person-years of follow-up, median follow-up 25.3 years, 1,106 CVD deaths). Fitness was measured by the Balke protocol and categorized according to treadmill time into low, moderate, and high fitness, with further stratification by CVD risk factor burden. Lifetime risk for CVD death determined by the National Death Index was estimated for fitness levels measured at ages 45, 55, and 65 years, with non-CVD death as the competing event.ResultsDifferences in fitness levels (low fitness vs. high fitness) were associated with marked differences in the lifetime risks for CVD death at each index age: age 45 years, 13.7% versus 3.4%; age 55 years, 34.2% versus 15.3%; and age 65 years, 35.6% versus 17.1%. These associations were strongest among persons with CVD risk factors.ConclusionsA single measurement of low fitness in mid-life was associated with higher lifetime risk for CVD death, particularly among persons with a high burden of CVD risk factors

Cardiorespiratory Fitness Is Inversely Associated With the Incidence of Metabolic Syndrome: A Prospective Study of Men and Women

Background - Few studies have reported the relationship between cardiorespiratory fitness and metabolic syndrome incidence, particularly in women. Methods and Results - We prospectively studied 9007 men (mean±SD, age, 44±9 years; body mass index, 25±3 kg/m2) and 1491 women (age, 44±9 years; body mass index, 22±2 kg/m2) who were free of metabolic syndrome and for whom measures of waist girth, resting blood pressure, fasting lipids, and glucose were taken during baseline and follow-up examinations. Baseline cardiorespiratory fitness was quantified as duration of a maximal treadmill test. Metabolic syndrome was defined with NCEP ATP-III criteria. During a mean follow-up of 5.7 years, 1346 men and 56 women developed metabolic syndrome. Age-adjusted incidence rates were significantly lower (linear trend P\u3c0.001) across incremental thirds of fitness in men and women. After further adjustment for potential confounders, multivariable hazard ratios for incident metabolic syndrome among men in the low, middle, and upper thirds of fitness, were 1.0 (referent), 0.74 (95% CI, 0.65 to 0.84), and 0.47 (95% CI, 0.40 to 0.54) linear trend (P\u3c0.001); in women, they were 1.0 (referent), 0.80 (95% CI, 0.44 to 1.46), and 0.37 (95% CI, 0.18 to 0.80) (linear trend P=0.01), respectively. Similar patterns of significant inverse association between fitness and metabolic syndrome incidence were seen when men were stratified on categories of body mass index, age, and number of baseline metabolic risk factors, but patterns were variable in women. Conclusions - Low cardiorespiratory fitness is a strong and independent predictor of incident metabolic syndrome in women and men. Clinicians should consider the potential benefits of greater cardiorespiratory fitness in the primary prevention of metabolic syndrome, particularly among patients who have already begun to cluster metabolic syndrome components

Muscular Fitness and All-Cause Mortality: Prospective Observations

Background: The beneficial effects of cardiorespiratory fitness on mortality are well known; however, the relation of muscular fitness, specifically muscular strength and endurance, to mortality risk has not been thoroughly examined. The purpose of the current study is to determine if a dose-response relation exists between muscular fitness and mortality after controlling for factors such as age and cardiorespiratory fitness. Methods: The study included 9105 men and women, 20-82 years of age, in the Aerobics Center Longitudinal Study who have completed at least one medical examination at the Cooper Clinic in Dallas, TX between 1981 and 1989. The exam included a muscular fitness assessment, based on 1-min sit-up and 1-repetition maximal leg and bench press scores, and a maximal treadmill test. We conducted mortality follow-up through 1996 primarily using the National Death Index, with a total follow-up of 106,046 person-years. All-cause mortality rates were examined across low, moderate, and high muscular fitness strata. Results: Mortality was confirmed in 194 of 9105 participants (2.1%). The age- and sex-adjusted mortality rate of those in the lowest muscular fitness category was higher than that of those in the moderate fitness category (26.8 v. 15.3 per 10,000 persons-years, respectively). Those in the high fitness category had a mortality rate of 20.6 per 10,000 persons-years. The moderate and high muscular fitness groups had relative risks of 0.64 (95% CI = 0.44-0.93) and 0.80 (95% CI = 0.49-1.31), adjusting for age, health status, body mass index, cigarette smoking, and cardiorespiratory fitness when compared with the low muscular fitness group. Conclusions: Mortality rates were lower for individuals with moderate/high muscular fitness compared to individuals with low muscular fitness. These findings warrant further research to confirm the apparent threshold effect between low and moderate/high muscular fitness and all-cause mortality

Muscular Fitness and All-Cause Mortality: Prospective Observations

Background: The beneficial effects of cardiorespiratory fitness on mortality are well known; however, the relation of muscular fitness, specifically muscular strength and endurance, to mortality risk has not been thoroughly examined. The purpose of the current study is to determine if a dose-response relation exists between muscular fitness and mortality after controlling for factors such as age and cardiorespiratory fitness. Methods: The study included 9105 men and women, 20-82 years of age, in the Aerobics Center Longitudinal Study who have completed at least one medical examination at the Cooper Clinic in Dallas, TX between 1981 and 1989. The exam included a muscular fitness assessment, based on 1-min sit-up and 1-repetition maximal leg and bench press scores, and a maximal treadmill test. We conducted mortality follow-up through 1996 primarily using the National Death Index, with a total follow-up of 106,046 person-years. All-cause mortality rates were examined across low, moderate, and high muscular fitness strata. Results: Mortality was confirmed in 194 of 9105 participants (2.1%). The age- and sex-adjusted mortality rate of those in the lowest muscular fitness category was higher than that of those in the moderate fitness category (26.8 v. 15.3 per 10,000 persons-years, respectively). Those in the high fitness category had a mortality rate of 20.6 per 10,000 persons-years. The moderate and high muscular fitness groups had relative risks of 0.64 (95% CI = 0.44-0.93) and 0.80 (95% CI = 0.49-1.31), adjusting for age, health status, body mass index, cigarette smoking, and cardiorespiratory fitness when compared with the low muscular fitness group. Conclusions: Mortality rates were lower for individuals with moderate/high muscular fitness compared to individuals with low muscular fitness. These findings warrant further research to confirm the apparent threshold effect between low and moderate/high muscular fitness and all-cause mortality

Distasteful nectar deters floral robbery

Toxic nectar is an ecological paradox[1,2]. Plants divert substantial resources to produce nectar that attracts pollinators [3], but toxins in this reward could disrupt the mutualism and reduce plant fitness [4]. Alternatively, such compounds could protect nectar from robbers [2], provided they do not significantly alter pollinator visitation to the detriment of plant fitness [1,5–8]. Indeed, very few studies have investigated the role of plant toxins in nectar for defence against nectar robbers [4,9,10]. Here, we compared two Aconitum species (A. napellus and A. lycoctonum) that have flowers specialized for long-tongued bumblebee pollinators (Bombus hortorum) but are occasionally robbed by short-tongued bumblebees (B. terrestris) [6,11–13]. Pollinator visits to flowers were much more frequent than by robbers but visits correlated negatively with nectar alkaloid concentration and declined sharply between 200-380ppm. However, alkaloid concentrations of > 20ppm were deterrent to B. terrestris suggesting robbers were less tolerant of nectar alkaloids. Nectar of both plant species contained similar concentrations of carbohydrates and toxic alkaloids, but A. lycoctonum was more likely to secrete nectar in each flower and was also visited more frequently by pollinators and robbers.  We conclude that alkaloids in Aconitum sp. nectar affect rates of both pollinator visitation and robbery but may have co-evolved with nectar availability to maintain the fitness benefits of specialized plant-pollinator relationships. Chemical defence of nectar is, however, ultimately constrained by pollinator gustatory sensitivity

A cluster randomised controlled trial of the clinical and cost-effectiveness of a 'whole systems' model of self-management support for the management of long- term conditions in primary care: trial protocol

BackgroundPatients with long-term conditions are increasingly the focus of quality improvement activities in health services to reduce the impact of these conditions on quality of life and to reduce the burden on care utilisation. There is significant interest in the potential for self-management support to improve health and reduce utilisation in these patient populations, but little consensus concerning the optimal model that would best provide such support. We describe the implementation and evaluation of self-management support through an evidence-based 'whole systems' model involving patient support, training for primary care teams, and service re-organisation, all integrated into routine delivery within primary care.MethodsThe evaluation involves a large-scale, multi-site study of the implementation, effectiveness, and cost-effectiveness of this model of self-management support using a cluster randomised controlled trial in patients with three long-term conditions of diabetes, chronic obstructive pulmonary disease (COPD), and irritable bowel syndrome (IBS). The outcome measures include healthcare utilisation and quality of life. We describe the methods of the cluster randomised trial.DiscussionIf the 'whole systems' model proves effective and cost-effective, it will provide decision-makers with a model for the delivery of self-management support for populations with long-term conditions that can be implemented widely to maximise 'reach' across the wider patient population.Trial registration numberISRCTN: ISRCTN9094004