BACKGROUND: There may be a link among stress, adrenal medullary activation, and the development of hypertension. Obesity is characterized by sympathetic activation and predisposes to hypertension, but may be associated with low or normal adrenal medullary activity. We hypothesized that plasma epinephrine (E) levels and adrenal medullary responsiveness to mental stress are lower in overweight than in lean borderline hypertensive subjects. METHODS: We compared groups of lean (n = 62) and overweight (n = 29) borderline hypertensive young men as well as lean (n = 36) and overweight (n = 7) normotensive young men from the same population. Plasma catecholamines and heart rate (HR) were measured at rest during a hyperinsulinemic glucose clamp and during mental arithmetic-induced stress. RESULTS: Plasma norepinephrine (NE) and E, HR, and responses to stress were increased in borderline hypertensive subjects. Our results showed that NE was increased only in lean borderline hypertensive subjects at rest, but in overweight subjects as well during stress, with DeltaNE being similar in lean and overweight subjects. We found that E was higher in lean than in overweight borderline hypertensive subjects at rest and during stress (both P
Sarcopenic muscular degeneration has been consistently identified as an independent risk factor for mortality in aging populations. Recent investigations have realized the quantitative potential of computed tomography (CT) image analysis to describe skeletal muscle volume and composition; however, the optimum approach to assessing these data remains debated. Current literature reports average Hounsfield unit (HU) values and/or segmented soft tissue cross-sectional areas to investigate muscle quality. However, standardized methods for CT analyses and their utility as a comorbidity index remain undefined, and no existing studies compare these methods to the assessment of entire radiodensitometric distributions. The primary aim of this study was to present a comparison of nonlinear trimodal regression analysis (NTRA) parameters of entire radiodensitometric muscle distributions against extant CT metrics and their correlation with lower extremity function (LEF) biometrics (normal/fast gait speed, timed up-and-go, and isometric leg strength) and biochemical and nutritional parameters, such as total solubilized cholesterol (SCHOL) and body mass index (BMI). Data were obtained from 3,162 subjects, aged 66-96 years, from the population-based AGES-Reykjavik Study. 1-D k-means clustering was employed to discretize each biometric and comorbidity dataset into twelve subpopulations, in accordance with Sturges' Formula for Class Selection. Dataset linear regressions were performed against eleven NTRA distribution parameters and standard CT analyses (fat/muscle cross-sectional area and average HU value). Parameters from NTRA and CT standards were analogously assembled by age and sex. Analysis of specific NTRA parameters with standard CT results showed linear correlation coefficients greater than 0.85, but multiple regression analysis of correlative NTRA parameters yielded a correlation coefficient of 0.99 (P
Cites: J Gerontol A Biol Sci Med Sci. 1999 Apr;54(4):M172-6 PMID 10219007
Cites: J Gerontol A Biol Sci Med Sci. 2006 Oct;61(10):1059-64 PMID 17077199
OBJECTIVES. To investigate the relationship between gonadal function, insulin and psychosocial stress in middle-aged men. DESIGN. A population-based, cross-sectional, observational study. SETTING. Glostrup Hospital, Copenhagen, Denmark. SUBJECTS. Four hundred and thirty-nine males, all aged 51 years. MAIN VARIABLES. Body-mass index (BMI), waist-to-hip ratio (WHR), insulin, C-peptide, free testosterone, luteinizing hormone (LH), lipids, fibrinogen, lung function tests (FVC, FEV1, PEF), blood pressure, a self-administered questionnaire with questions on psychosocial variables, lifestyle and self-rated health. RESULTS. Free testosterone correlated inversely (P
BACKGROUND: The objective of this study was to estimate the risk of severe osteoarthritis, with the need for arthroplasty, in the knee and/or hip according to body mass index (BMI) both within a normal range and in persons with high BMI. Furthermore, we wanted to study the significance of smoking. METHODS: This study identifies male construction workers participating in a national health control program (n = 320,192). The incidence rate for joint replacement was found by matching with the Swedish hospital discharge register between 1987 and 1998. BMI and smoking habit was registered at the time of the health examination. RESULTS: In total 1495 cases of osteoarthritis of the hip and 502 cases of osteoarthritis of the knee were identified and included in this analysis. The incidence rate was found to increase linearly to the BMI even within low and 'normal' BMI. The relative risk for osteoarthritis of the hip was more than two times higher in persons with a BMI of 20-24 than in men with a BMI 17-19. There was almost a doubling of the risk of severe knee osteoarthritis with an increase in BMI of 5 kg/m2. Smoker had a lower risk of osteoarthritis than non-smokers and ex-smokers. CONCLUSIONS: BMI is an important predictor of osteoarthritis even within normal BMI. A decreased risk of osteoarthritis of the hip was found in smokers, but the effect was weak compared to that of BMI or age. Contrary to studies of radiographic osteoarthritis our study indicates higher risk of hip than of knee osteoarthritis.
Several studies have shown that insulin action deteriorates with age, possibly mediated through accumulation of abdominal fat. We determined peripheral insulin action in elderly and younger men who had participated in a large population study (the Tromsø Study). To 15 elderly participants aged 71 to 77 years, we individually matched 15 younger participants aged 31 to 33 years (Y1) by body mass index (BMI). A second young group (Y2) comprised 15 participants also aged 31 to 33 years, but with BMI representative of this age group in the population study. All underwent hyperinsulinemic euglycemic clamps (0.4 mU/kg/min), oral glucose tolerance tests, and determinations of Vo2max. Insulin sensitivity index (ISI=glucose disposal per kg fat-free mass [FFM] divided by steady-state insulin concentration) did not differ between the elderly and Y1, but was higher in Y2 (0.10+/-0.01, 0.12+/-0.01, and 0.17+/-0.02, P=.0011 by analysis of variance [ANOVA]). Adjustment by waist circumferences (analysis of covariance [ANCOVA]) abolished this difference. In univariate analysis of pooled data, ISI correlated negatively to body fat indices, serum triglycerides, and free fatty acids (FFA), and positively to Vo2max. In multiple regression analysis, waist circumference and triglycerides were the only independent predictors of insulin sensitivity, whereas age had no impact. The results confirm that the decline in insulin action seen in elderly people is related to increased abdominal fat rather than aging per se.
Lipoprotein(a) [Lp(a)] is an important risk factor for cardiovascular disease. Alcohol is one of the few nongenetic factors that lower Lp(a) levels, but the metabolic mechanisms of this action are unknown. Alcohol inhibits the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis. Alcohol might also affect IGF-binding protein-1 (IGFBP-1), which is an acute inhibitor of IGF-I. We studied how alcohol withdrawal affects Lp(a) levels and the GH/IGF-I/IGFBP-1 axis. Male alcohol abusers (n=27; 20 to 64 years old) were monitored immediately after alcohol withdrawal for 4 days. Twenty-six healthy men, mainly moderate drinkers, served as control subjects. Fasting blood samples were drawn to determine Lp(a), IGF-I, and IGFBP-1 (by ELISA, RIA, and immunoenzymometric assay, respectively). Nocturnal (12 hours) urine collection was performed in 9 alcoholics and 11 control subjects for GH analyses (RIA). The groups were similar in age and body mass index. Lp(a), GH, and IGF-I tended to be lower and IGFBP-1 higher in the alcoholics immediately after alcohol withdrawal than in the control subjects. During the 4-day observation in alcoholics, Lp(a) levels increased by 64% and IGF-I levels by 41%, whereas IGFBP-1 levels decreased by 59% (P
Low hemoglobin concentration is associated with increased mortality, but there is disagreement with regard to the clinical definition of anemia. We aimed to evaluate the prevalence, clinical correlates and association with total and cause-specific long-term mortality across the hemoglobin distribution and for previously proposed definitions of anemia. Blood hemoglobin concentration and mean corpuscular volume was measured in participants of the Malmö diet and cancer study-a prospective cohort study, and related to baseline characteristics and outcomes during follow-up. Primary endpoints were all-cause mortality, cardiovascular mortality and cancer-related mortality. A U-shaped association of hemoglobin with total mortality was observed in spline regression analyses, with nadir at hemoglobin 150 g/L among men and 130 g/L among women. Mortality increased steeply with more strict definitions of anemia, hazard ratio: 1.36, 1.94 and 2.16 for hemoglobin
OBJECTIVE: To examine whether modifiable lifestyle factors such as smoking, obesity, physical activity and intake of alcohol or caffeinated drinks were associated with urinary incontinence in women. DESIGN: Cross sectional population-based study. SETTING: The Norwegian Epidemiology of Incontinence in the County of Nord-Tr?ndelag (EPINCONT) Study is part of a large survey performed in a county in Norway during 1995-1997. POPULATION: Women >/=20 years (n = 34,755, 75% of the invited) attended the first part of the survey and received the questionnaire. There were 27,936 (80% of source population) women who completed the incontinence part of the questionnaire. METHODS: Questionnaire covering several health topics including urinary incontinence was received at a screening station. Logistic regression analysis was used to adjust for confounding and to establish associations with the different outcomes under investigation: any incontinence, severe incontinence and stress, urge and mixed subtypes. MAIN OUTCOME MEASURES: Effect measure were odds ratios with corresponding 95% confidence intervals. RESULTS: Former and current smoking was associated with incontinence, but only for those who smoked more than 20 cigarettes per day. Severe incontinence was weakly associated with smoking regardless of number of cigarettes. The association between increasing body mass index and incontinence was strong and present for all subtypes. Increasing levels of low intensity physical activity had a weak and negative association with incontinence. Tea drinkers were at slightly higher risk for all types of incontinence. We found no important effects of high intensity physical activity, intake of alcohol or coffee. CONCLUSIONS: Several potentially modifiable lifestyle factors are associated with urinary incontinence. Highest odds ratios were found for body mass index, heavy smoking and tea drinking.
To investigate whether the high prevalence of symptoms related to obstructive sleep apnoea syndrome (OSAS) in a bronchitic cohort is correlated with the bronchitic symptoms or lung function impairment we examined two cohorts with bronchitic symptoms (n = 357 and 82) and a reference group who had reported no respiratory symptoms in a previous survey in 1986 (n = 140). The study was a part of the Obstructive Lung Disease in Northern Sweden Study and included clinical examination and lung function tests. Although lung function measured as FEV1 percentage predicted was correlated with bronchitic symptoms we found that bronchitic symptoms and body mass index but not lung function impairment were correlated with symptoms related to obstructive sleep apnoea. According to our findings it was the various bronchitic symptoms such as longstanding cough, wheezing, sputum production and chronic productive cough that were correlated with OSAS symptoms. This might be due to increased upper airway swelling or increased upper airway resistance, and lung function impairment does not seem to be responsible for the high prevalence of symptoms related to obstructive sleep apnoea in this bronchitic cohort.