Cycle-to-cycle flow variations in a square duct with a symmetrically oscillating constriction.

Spatially and temporally resolved Digital Particle Image Velocimetry (DPIV) measurements are presented of flow complexities in a nominally two-dimensional, symmetric, duct with an oscillating constriction. The motivation for this research lies in advancing the state-of-the-art in applying integral control volume analysis to modeling unsteady internal flows. The specific target is acoustic modeling of human phonation. The integral mass and momentum equations are directly coupled to the acoustic equations and provide quantitative insight into acoustic source strengths in addition to the dynamics of the fluid-structure interactions in the glottis. In this study, a square cross-section duct was constructed with symmetric, computer controlled, oscillating constrictions that incorporate both rocking as well as oscillatory open/close motions. Experiments were run in a free-surface water tunnel over a Strouhal number range, based on maximum jet speed and model length, of 0.012 - 0.048, for a fixed Reynolds number, based on maximum gap opening and maximum jet speed, of 8000. In this study, the constriction motions were continuous with one open-close cycle immediately following another. While the model and its motions were nominally two-dimensional and symmetric, flow asymmetries and oscillation frequency dependent cycle-to-cycle variations were observed. These are examined in the context of terms in the integral conservation equations.

Lower urinary tract symptoms increase the risk of falls in older men.

OBJECTIVE To evaluate the association of lower urinary tract symptoms (LUTS) with the risk of falls in elderly community-dwelling men. SUBJECTS AND METHODS We evaluated 5872 participants in the Osteoporotic Fractures in Men, a prospective cohort study of risk factors for falls and osteoporotic fractures among community-dwelling men aged > or =65 years. The primary outcome was the 1-year cumulative incidence of falls in men with moderate or severe, vs mild LUTS at baseline, as measured by the American Urological Association Symptom Index. We used Poisson regression models and considered multiple variables as potential confounders. RESULTS At baseline, 3188 (54%) reported mild, 2301 (39%) moderate, and 383 (7%) severe LUTS. Compared with men who had mild symptoms, the adjusted 1-year cumulative incidence of falls was significantly higher among men with moderate or severe LUTS. The risk of at least one fall was increased by 11% among those with moderate (relative risk 1.11, 95% confidence interval, CI, 1.01-1.22; P = 0.02) and by 33% among those with severe LUTS (1.33, 1.15-1.53; P < 0.001). Further, those with moderate LUTS had a 21% (1.21, 1.05-1.40; P = 0.01) and those with severe LUTS a 63% (1.63, 1.31-2.02; P < 0.001) greater risk of at least two falls. LUTS most strongly associated with falls were urinary urgency, difficulty initiating urination, and nocturia. CONCLUSIONS Moderate and severe LUTS independently increase the 1-year risk of falls, particularly recurrent falls, in community-dwelling older men. Because of the serious consequences of falls, these results might justify the routine assessment of LUTS with a validated questionnaire in the primary care of this population.

Vitamin D deficiency in older men.

CONTEXT: Vitamin D deficiency is not adequately evaluated in older men. OBJECTIVE: The aim of the study was to determine the prevalence of vitamin D deficiency and identify risk factors for its occurrence. DESIGN AND SETTING: We conducted a cross-sectional evaluation of 1606 older men in the general community who were enrolled in the Osteoporotic Fractures in Men Study. PARTICIPANTS: A randomly selected subcohort of a large population of men from six U.S. communities participated in the study. MAIN OUTCOME MEASURES: Serum concentrations of 25-hydroxyvitamin D(2) [25(OH)D(2)] and 25(OH)D(3) were measured using mass spectrometry. RESULTS: Deficiency [25(OH)D <20 ng/ml] was present in 26%, and insufficiency (<30 ng/ml) was present in 72%. Deficiency was particularly common among men during the winter and spring (especially in the northern communities) and in the oldest and more obese men. For instance, in Caucasian men in winter or spring who were >80 yr old, did not engage in lawn/garden work, and had a body mass index greater than 25 kg/m(2) and vitamin D intake below 400 IU/d, the prevalence of vitamin D deficiency was 86%. 25(OH)D(2) levels were present in a small fraction of men and accounted for a low proportion of total 25(OH)D levels. The use of vitamin D supplements was reported by 58% of men, but supplement use had a small effect on total 25(OH)D levels and, despite supplement use, low levels remained frequent. CONCLUSIONS: Vitamin D deficiency is common in older men and is especially prevalent in obese, sedentary men living at higher latitudes. Use of vitamin D supplements at levels reported here did not result in adequate vitamin D nutrition.

The association between advertising and calls to a tobacco quitline.

OBJECTIVE: This study assessed the cost effectiveness of different types of television and radio advertisements and the time of day in which advertisements were placed in generating calls to the Oregon tobacco quitline. DESIGN: Cost effectiveness was measured by cost per call, calculated as the cost of advertising divided by the number of quitline calls generated by that advertising. Advertising was bought in one-week or two-week blocks and included 27 daytime television buys, 22 evening television buys and 31 radio buys. RESULTS: Cost effectiveness varied widely by medium, time of day and advertisement used. Daytime television was seven times more cost effective than evening television and also more cost effective than radio. The most effective advertisements at generating quitline calls were real life testimonials by people who lost family members to tobacco and advertisements that deal practically with how to quit. CONCLUSIONS: Placement of television advertisements during the day versus the evening can increase an advertisement's effectiveness in generating calls to a quitline. Some advertising messages were more effective than others in generating calls to a quitline. Quitline providers can apply findings from previous research when planning media campaigns. In addition, call volume should be monitored in order to assess the cost effectiveness of different strategies to promote use of the quitline.

Identification of vertebral fracture and non-osteoporotic short vertebral height in men: the MrOS study.

UNLABELLED: Non-osteoporotic SVH may mimic VF but is excluded in ABQ. In men, this led to discordance between ABQ and other methods, but SVH was not linked to low bone density. Exclusion of SVH could reduce false positives. INTRODUCTION: Non-osteoporotic short vertebral height (SVH) may mimic vertebral fracture (VF). The aims were to (1) compare the prevalence of VF in elderly men using the algorithm-based qualitative (ABQ), semiquantitative (SQ), and triage-quantitative morphometric (triage-QM) methods; (2) identify reasons for discordance between methods; and (3) determine whether SVH identified by ABQ is linked to low BMD. MATERIALS AND METHODS: We studied a subset of 732 men ages > or =65 yr participating in the Osteoporotic Fractures in Men (MrOS) Study. Criteria for VF were (1) ABQ: endplate depression; (2) SQ: estimated vertebral height reduction > or =20%; (3) triage-QM: vertebral height ratio >3 SD below the reference mean, on radiographs showing evidence of VF. Criteria for SVH (ABQ) were apparent "reduction" in vertebral height > or = approximately 15%, without evidence of endplate depression. RESULTS: The prevalence of at least one VF was 10% (ABQ); 13% (SQ) and 11% (QM-triage) and of at least one SVH (ABQ) was >50%. Agreement between methods was moderate (kappa = 0.42-0.62). Discordance between methods related mainly to classification of mild thoracic wedging or possible traumatic VF by ABQ. Mean BMD was lower in men with VF (any diagnostic method) than in those without (two-sample t-test, p < 0.05). For ABQ, BMD was similar in men with SVH (no VF) and men with normal vertebrae (ANOVA, p > 0.05). Mean BMD was significantly lower than expected in 40 men with VF identified by all three methods and average or more than average in those identified by a single method. CONCLUSIONS: Among elderly men (1) the prevalence of VF ranges from 10% to 13%: (2) agreement between diagnostic methods is moderate: discordance relates mainly to differential classification of mild thoracic deformities or ABQ definition of VF as traumatic; and (3) SVH identified by ABQ is common and not linked to low BMD.

Prevalence, severity, and health correlates of lower urinary tract symptoms among older men: the MrOS study.

OBJECTIVES: To describe the prevalence, severity, and health correlates of lower urinary tract symptoms (LUTS) in older community-dwelling U.S. men. METHODS: We performed a cross-sectional analysis from a cohort study recruited from six U.S. clinical centers. This analysis included 5284 men without a history of prostate cancer who were at least 65 years of age. Participants completed questionnaires regarding the presence and severity of LUTS, including the American Urological Association Symptom and Bother indexes. Health status measures included the Medical Outcomes Survey SF-12 and self-rated health and instrumental activities of daily living. RESULTS: LUTS were absent in 2.3%, mild in 51.6%, moderate in 39.6%, and severe in 6.6%. Dissatisfaction with the urinary symptoms increased with LUTS severity (P <0.001); 19.8% of moderate and 58.1% of men with severe LUTS reported feeling mostly unsatisfied to terrible with their present urinary symptoms. The prevalence, severity, and dissatisfaction with LUTS increased with age. Men reporting moderate or severe LUTS were 1.41-fold (95% confidence interval 1.23 to 1.61) and 1.51-fold (95% confidence interval 1.23 to 1.85) more likely to rate their overall health quality as fair to very poor for their age instead of good to excellent, even after controlling for age and comorbid conditions. Increased LUTS also was independently associated with increased impairment in instrumental activities of daily living and poorer SF-12 scores. CONCLUSIONS: Moderate-to-severe LUTS is common in community-dwelling elderly U.S. men. In this study, LUTS severity was associated with poorer health quality and a greater prevalence of an inability to perform activities of daily living. The association of LUTS severity with poor health warrants increased clinical attention.

Endogenous testosterone levels, physical performance, and fall risk in older men.

BACKGROUND: Gonadal steroid levels decline with age in men. Whether low testosterone levels affect the development of common age-related disorders, including physical functioning and falling, is unclear. METHODS: This longitudinal, observational follow-up study sought to determine whether low testosterone levels are associated with physical performance and fall risk in older men. A total of 2587 community-based men aged 65 to 99 years were selected using a stratified random sampling scheme from a study cohort of 5995 volunteers. Bioavailable testosterone and estradiol levels and physical performance measures were determined from baseline. Incident falls were ascertained every 4 months during 4 years of follow-up. Generalized estimating equations were used to estimate risk ratios for the relation of sex steroids to falls. RESULTS: Fifty-six percent of the men reported at least 1 fall; many fell frequently. Lower bioavailable testosterone levels were associated with increased fall risk. Men with testosterone levels in the lowest quartile had a 40% higher fall risk than those in the highest quartile. The effect of low testosterone levels was most apparent in younger men (65-69 years) (relative risk, 1.8; 95% confidence interval, 1.2-2.7); testosterone level was not associated with falls in the oldest men (>/=80 years). Lower testosterone concentrations were associated with reduced physical performance. However, the association between low testosterone levels and fall risk persisted despite adjustment for performance. CONCLUSIONS: Falls were common among older men. Fall risk was higher in men with lower bioavailable testosterone levels. The effect of testosterone level was independent of poorer physical performance, suggesting that the effect of testosterone on fall risk may be mediated by other androgen actions.

Dimensions and volumetric BMD of the proximal femur and their relation to age among older U.S. men.

UNLABELLED: We measured femoral neck and shaft dimensions and volumetric BMD with QCT. Relations of these measures to age were quantified in a cross-sectional study among 3358 men 65-100 years old. Relations of femoral neck dimensions and vBMD to age differed from those in the shaft, indicating that patterns of bone modeling and remodeling in the neck and shaft are distinct. INTRODUCTION: Little is known about population variation in dimensions and volumetric BMD of the proximal femur or the relation of these measures to age among older men. MATERIALS AND METHODS: In a cross-sectional study, dimensions and volumetric BMD (vBMD) in the femoral neck and shaft were obtained from QCT scans among 3358 men 65-100 years of age in the Osteoporotic Fractures in Men cohort. Total bone size and size of the cortical and medullary compartments were measured with volumes in the femoral neck and with areas in the shaft. We quantified distributions of these measures and examined their relations to age with multivariable linear regression. RESULTS: Population variation in femoral neck and shaft dimensions and vBMD was substantial. In the femoral neck, total volume was minimally related to age, whereas cortical volume was 5% smaller and medullary volume was 10% larger (both p < 0.0001) in the oldest (85+ years) compared with the youngest (65-69 years) men. Across these ages, the percent of cortical bone declined from 46% to 42% (p < 0.0001). Integral and trabecular vBMD were 9% and 22% lower, whereas DXA femoral neck BMD was 4% lower, in the older men. Neck cortical vBMD was unrelated to age. In the shaft, cross-sectional area and medullary area were 9% and 22% larger, respectively, in the oldest men (both p < 0.0001), but cortical area was unchanged with age. The percent of cortical bone declined from 69% to 65% across these ages (p < 0.0001). Shaft cortical BMD was 4% lower in the older men (p < 0.0001). CONCLUSIONS: There is substantial diversity of femoral morphology and vBMD among older U.S. men. Patterns indicative of modeling and remodeling in the femoral neck were distinct from those in the shaft. Notably, changes in periosteal and endosteal dimensions that underlie cortical thinning appear to differ in the neck and shaft.

Testosterone and estradiol among older men.

CONTEXT: Testosterone and estradiol levels decline with age in men. This change may affect multiple clinical outcomes, but there have been few reports of the distribution and correlates of testosterone and estradiol concentrations in elderly men. OBJECTIVE: The purpose of these studies was to assess sex steroid levels in a large cohort of older men. DESIGN: We conducted a cross-sectional cohort evaluation. SETTING: Community-dwelling men were studied at six academic medical centers in the United States. PARTICIPANTS: The Osteoporotic Fractures in Men Study is a prospective cohort of men aged at least 65 yr. In these studies, a randomly selected stratified subsample of 2623 participants was analyzed. MAIN OUTCOME MEASURES: We assessed levels of total and free testosterone and estradiol and SHBG. RESULTS: Age was inversely associated with free testosterone and free estradiol levels (P for trend = 0.001 for both). Notably, at any age, there was substantial variation in levels of each hormone. Free testosterone levels were lower in men with greater body mass index, lower SHBG, and poorer self-reported health status and in those of Asian race. Free estradiol concentrations were lower in men with lower body mass index and higher SHBG levels. Free estradiol and free testosterone were modestly correlated (r = 0.20; P < 0.001), but at any level of free testosterone, there was considerable variation in free estradiol levels. CONCLUSIONS: This is the largest cohort of older men in which sex steroid levels are available, and it demonstrates that testosterone and estradiol, and their free fractions, tend to decline with age even among older men. However, substantial variation is also present. The relationships between sex steroid levels and their consequences in aging are likely to be complex.

Predictors of glucose control in children and adolescents with type 1 diabetes mellitus.

AIMS: To evaluate the glucose control [(as measured by hemoglobin A1c (HbA1c)], the factors associated with glycemic control, and possible explanations for these associations in a sample of children and adolescents with type 1 diabetes. METHODS: Data were collected on 155 children and adolescents, with type 1 diabetes mellitus, attending a multidisciplinary diabetes clinic in Portland, OR. Patients' hospital charts were reviewed to determine demographic factors, disease-related characteristics, and HbA1c level. RESULTS: Mean percent HbA1c was 9.3. Adolescents between the ages of 14 and 18 yr were in poorer metabolic control (adjusted mean percent HbA1c 0.56 higher than children 2-8 yr). Children who attended the clinic three to four times in the previous year were in better control (adjusted mean percent HbA1c 0.46 lower than those who visited two or fewer times and 1.11 lower than those who attended five or more times). Children with married parents were in better glycemic control than those of single, separated, or divorced parents (adjusted mean percent HbA1c 0.47 lower for children of married parents). This effect appeared to be mediated, in part, by the number of glucose checks performed per day. CONCLUSIONS: This study suggests that adolescents should be targeted for improved metabolic control. Diabetes team members need to be aware of changing family situations and provide extra support during stressful times. Regular clinic attendance is an important component of intensive diabetes management. Strategies must be developed to improve accessibility to the clinic and to identify patients who frequently miss appointments.