A Geospatial Analysis of Social and Structural Determinants of Health and High HIV Prevalence in Alabama, USA.

OBJECTIVE: This study utilizes geospatial analytic techniques to examine HIV hotspots in Alabama leveraging Medicaid utilization data. METHODS: This cross-sectional study leveraged Medicaid utilization data from Alabama's 67 counties, averaging 9,861 Medicaid recipients aged > 18 years old per county. We used Alabama Medicaid administrative claims data from January 1, 2016, to December 31, 2020, to identify individuals with HIV. Using Microsoft SQL Server, we obtained the average annual count of HIV Medicaid claims in each of the 67 Alabama counties (numerator) and the number of adult Medicaid recipients in each county (denominator), and standardized with a multiplier of 100,000. We also examined several other area-level summary variables (e.g., non-high school completion, income greater than four times the federal poverty level, social associations, urbanicity/rurality) as social and structural determinants of health. County-boundary choropleth maps were created representing the geographic distribution of HIV rates per 100,000 adult Medicaid recipients in Alabama. Leveraging ESRI ArcGIS and local indicators of spatial association (LISA), results were examined using local Moran's I to identify geographic hotspots. RESULTS: Eleven counties had HIV rates higher than 100 per 100,000. Three were hotspots. Being an HIV hotspot was significantly associated with relatively low educational attainment and less severe poverty than other areas in the state. CONCLUSIONS: Findings suggesting that the HIV clusters in Alabama were categorized by significantly less severe poverty and lower educational attainment can aid ongoing efforts to strategically target resources and end the HIV epidemic in U.S.' Deep South.

A qualitative study examining the preparedness of dental hygiene students for a service-learning placement in residential aged care.

INTRODUCTION: The aim of this qualitative study was to measure the effect of a specifically designed orientation re-enactment DVD used to facilitate dental hygiene students transition from the classroom to a Residential Aged Care Facility (RACF) service-learning placement with less personal anxiety and more confidence in their role during the placement. METHODOLOGY: Final year students (n = 47) were randomly allocated to one of 17 RACFs on the NSW, Central Coast, Australia. All students were then randomly allocated to a two-group study with the active group assigned to view the DVD prior to their placement. Students who viewed the DVD were asked not to discuss the content with students who were assigned to the control group. Post-placement focus groups were organized, recorded and transcribed verbatim. Data were collated, analysed and unitized into emergent themes. Representative quotes are presented in the results. The study was informed by 4 years of previous quantitative and qualitative process evaluation of the RACF programme. RESULTS: Focus group discussions identified that those students who had seen the DVD reported a shorter timeframe to successfully transition from the classroom to the RACF and stated that the DVD provided them with a realistic expectation of the RACF environment and their role in the placement experience. CONCLUSION: The orientation DVD reduced student anxiety and improved student confidence in their role during the placement by providing a realistic orientation of the RACF environment.

Attitudes and barriers to providing dietary advice: perceptions of dental hygienists and oral health therapists.

OBJECTIVES: Effective dietary counselling in a dental setting can significantly reduce the risk of oral disease. However, studies suggest that dental professionals are not instigating dietary advice on a regular basis, and there is a lack of current information of the barriers experienced that limit the delivery of dietary advice. The aim of this study was to investigate the current attitudes and practice behaviours of dental hygienists and oral health therapists in NSW, Australia, regarding dietary advice, and identify the barriers that limit its delivery. METHODS: A convenience sample of dental hygienists and oral health therapists were surveyed using a mail-out questionnaire. The questionnaire investigated the demographic data of participants, the attitudes and practice behaviours of participants, the perceived barriers and current dietary resources accessed by participants. RESULTS: Of 987 dental hygienists and oral health therapists, 426 participants responded. The study results suggest that many dental hygienists and oral health therapists have positive beliefs regarding the importance of dietary counselling. However, there are a multitude of barriers preventing the delivery of dietary advice; these include time, patient compliance, patient knowledge of nutrition topics, personal counselling skills and practitioners' knowledge of nutrition. CONCLUSION: Whilst dental hygienists and oral health therapists recognize the importance of diet and have positive attitudes towards providing dietary advice to patients, this study identified many barriers preventing implementation in practice. This information may be used to develop targeted strategies aimed at overcoming these barriers and improving behaviours.

Senior Smiles: preliminary results for a new model of oral health care utilizing the dental hygienist in residential aged care facilities.

OBJECTIVES: The aim of this study was to determine whether a qualified dental hygienist could improve oral health outcomes for residents living in residential aged care facilities on the Central Coast of New South Wales, Australia. METHODS: A qualified dental hygienist undertook a 24-week oral hygiene intervention in five residential aged care facilities to test the Senior Smiles, oral health model of care. The facilities were invited to take part in the research, which was funded by a grant from NSW Medicare Local, Erina. Residents were asked to consent to having oral health risk assessments, oral healthcare plans and to receiving referrals for treatment where needed. Pre- and post-intervention plaque scores were recorded for residents and P values calculated using a paired t-test. In addition, the number of residents examined, treated and referred for more complex dental care was recorded. RESULTS: The statistical analysis program, SPSS, was used to conduct a paired t-test to compare pre- and post-intervention plaque scores on residents from the 5 RACFs. A statistically significant result of P < 0.0001 showed the intervention of the dental hygienist was effective in reducing plaque scores in residents across the 5 RACFs. CONCLUSION: The Senior Smiles model of care provided residents with preventive oral hygiene care, referral pathways for complex dental treatment needs and established a formal management programme for ongoing oral health care within the RACFs. The Senior Smiles model of care is successful and transportable.

An assessment of the educational value of service-learning community placements in residential aged care facilities.

AIMS: The aim of this study was to determine whether dental hygiene students attending residential aged care facilities (RACFs) during a placement programme gained any knowledge about the oral care of elderly patients and the RACF environment. LOCATION: Aged Care Facilities on the Central Coast of New South Wales, Australia. METHODOLOGY: Final year dental hygiene students undertook a 12-week placement, one day per week, in one of 17 residential aged care facilities on the NSW Central Coast. They were asked to complete pre-placement and post-placement questionnaires, which recorded their knowledge of medical, dental and environmental issues related to older people. The placement questionnaires used five point Likert scales, ranging from strongly agree to strongly disagree, pre- and post-mean scores were produced for each question and P values calculated using a paired t-test. RESULTS: Thirty-three students attended the placement, 26 (79%) completed both the pre- and post-placement questionnaires. Post-placement mean scores as compared to pre-placement mean scores showed significant improvement in student knowledge of medical (P < 0.05) and dental (P < 0.05) conditions specific to the older person and improvement in knowledge (P < 0.05) about the residential aged care facility environment. CONCLUSION: The placement programme enhanced student knowledge across three subject categories; medical and dental conditions of the older person and the structure and services of the residential aged care environment.

Oral health education strategies for patients living with cardiovascular disease within hospital settings: a scoping review.

Objective: To identify and describe the impact of current oral health education programmes provided to patients in cardiology hospital wards and outpatient clinics. Methods: This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Scoping Reviews statement. Searches were conducted using electronic databases: Cochrane, Medline, and Scopus, as well as grey literature searching. Results: Three eligible studies were identified. All included studies reported generalised poor oral health in their participants at baseline, with significant improvement at follow-up. They all reported significant reductions in plaque deposits and gingival bleeding. One study reported significantly less bacteria on participant tongues, as well as fewer days with post-operative atrial fibrillation in the intervention group. Furthermore, in this study, one patient in the intervention group developed pneumonia, whilst four patients in the control group did. Conclusion: Oral health education for patients with cardiovascular disease is limited and many have poor oral health. Educational programmes to improve oral health behaviours in patients with cardiovascular disease can improve both oral and general health outcomes. Implications for public health: Oral disease is a modifiable risk factor for cardiovascular disease. Integrating oral health education into cardiology hospital settings is a simple strategy to improve access to oral health information and improve both oral and cardiovascular outcomes.

Reflective folios for dental hygiene students: what do they tell us about a residential aged care student placement experience?

INTRODUCTION: Community-based education programmes provide students with an experiential learning opportunity in a real-life context. The purpose of this study was to examine reflective journals to identify students' experiences and perceived learning during a 12-week placement programme in residential aged care facilities (RACF) on the NSW Central Coast, Australia. METHODOLOGY: All final year dental hygiene students from the University of Newcastle, Australia attended an aged care orientation workshop prior to commencing the RACF student placement programme. Throughout the placement, students were asked to record their educational experiences in reflective journals. Student reflections were based on the 'Gibbs Reflective Cycle', diarising experiences and feelings. Qualitative data was analysed using the constant comparative method and unitised to identify emergent themes. RESULTS: Sixty-seven students completed reflective journals during the placement programme; emergent themes indicated students felt ill-prepared for the placement programme despite attending the orientation workshop. They were apprehensive and nervous prior to commencement of the placement. The general consensus after week 6 was that the placement became a more positive experience where students began to feel comfortable in the RACF environment and residents, and staff started to respond more positively to their presence. Overall, they thought the placement was challenging and confronting, but had improved their skills and knowledge in care of older people and increased their confidence in working with other healthcare professionals. CONCLUSION: The reflective journals provided students with the opportunity to record and reflect on their experience and perceived learning during the placement programme. Student reflections identified negative experiences at the commencement of the placement, suggesting a need for additional orientation prior to the RACF programme.

A cross-sectional evaluation of seasonality as a determinant of endothelial function.

Endothelium-dependent vasodilation is impaired in obese versus lean humans. We set out to evaluate whether agonist-mediated endothelium-dependent vasodilation varies by season in a cross-sectional dataset of lean and obese humans, and whether this effect differed by obesity status. All vascular studies performed in our laboratory over a 12 year period from 1997 to 2009 were evaluated. Endothelium-dependent vasodilation was measured invasively using thermodilution in the leg as the response to intra-arterially infused methacholine chloride. Resting blood pressure was measured concurrently by cuff and intra-arterially. The association of endothelium-dependent vasodilation and blood pressure measurements with season was evaluated, comparing responses in lean and obese subjects. Endothelium-dependent vasodilation differed between lean and obese subjects, and varied across seasons (p=0.02), but without an interaction between season effect and obesity status. The proportion of obese versus lean subjects differed significantly across seasons in our dataset, and after adjusting for this factor the apparent seasonal variation in endothelium-dependent vasodilation was lost (p=0.12), and was not present in either lean or obese subjects separately. Systolic arterial blood pressure varied across seasons, and this effect remained significant after adjusting obesity status (p=0.019 and p=0.043 for blood pressures measured intra-arterially and by cuff respectively). In our cross-sectional dataset, seasonal variations in blood pressure were seen but we did not observe an association between season and endothelium-dependent vasodilation in lean or obese subjects.

Microcalorimeter measurement of x-ray spectra from a high-temperature magnetically confined plasma.

A NASA-built x-ray microcalorimeter spectrometer has been installed on the MST facility at the Wisconsin Plasma Physics Laboratory and has recorded x-ray photons emitted by impurity ions of aluminum in a majority deuterium plasma. Much of the x-ray microcalorimeter development has been driven by the needs of astrophysics missions, where imaging arrays with few-eV spectral resolution are required. The goal of our project is to adapt these single-photon-counting microcalorimeters for magnetic fusion energy research and demonstrate the value of such measurements for fusion science. Microcalorimeter spectrometers combine the best characteristics of the x-ray instrumentation currently available on fusion devices: high spectral resolution similar to an x-ray crystal spectrometer and the broadband coverage of an x-ray pulse height analysis system. Fusion experiments are increasingly employing high-Z plasma-facing components and require measurement of the concentration of all impurity ion species in the plasma. This diagnostic has the capability to satisfy this need for multi-species impurity ion data and will also contribute to measurements of impurity ion temperature and flow velocity, Zeff, and electron density. Here, we introduce x-ray microcalorimeter detectors and discuss the diagnostic capability for magnetic fusion energy experiments. We describe our experimental setup and spectrometer operation approach at MST, and we present the results from an initial measurement campaign.

Postprandial lipaemia, oxidative stress and endothelial function: a review.

AIMS: Postprandial lipaemia-induced endothelial dysfunction is felt to be mediated by increases in oxidative stress. In this review, we have examined the cross-sectional relationships found among these three variables. METHODS: We found 20 studies conducted by 16 independent investigative teams through a Medline search from 1980 to 2008; studies were required to report correlations between at least two of the three variables of interest in studies of humans. This review is divided into (i) discussions on the biomarkers and other measures of postprandial lipaemia, oxidative stress and endothelial function; (ii) associations reported among the three variables; and (iii) other considerations including alternative intervention studies. RESULTS: Triglycerides and free fatty acids are robust and well-standardised biomarkers of lipaemia. Measures of oxidative stress ranged from electron spin techniques to measures of lipid peroxidation and are limited by lack of standardisation. Brachial artery flow-mediated dilatation is the most commonly used measure of endothelial function. The associations between postprandial lipaemia and oxidative stress and between postprandial lipaemia and endothelial function are strong and consistent. However, the association between postprandial oxidative stress and endothelial function appears weak, at least using current approaches to measurement of oxidative stress. DISCUSSION AND CONCLUSIONS: These observations are consistent with the proposed concept that oxidative stress mediates the adverse effects of postprandial lipaemia on endothelial function; they are limited by the difficulties in measuring oxidative stress. Efforts directed at optimising and standardising the measurement of oxidative stress will be of value in future works in this area.

Time of day for exercise on blood pressure reduction in dipping and nondipping hypertension.

UNLABELLED: Time of day (TOD) for exercise may influence blood pressure (BP) reduction in hypertension because of the diurnal variation of BP and the duration of BP reduction following a single bout of exercise. The purpose of this study was to observe the effects of TOD for exercise on ambulatory blood pressure reduction in dipping (n=5) and nondipping (n=9) hypertension (<10% drop in nighttime BP (BP(night))). HYPOTHESES: (1) evening exercise (PM(ex)) would exhibit a greater BP(night) reduction in Non-Dippers than Dippers, (2) morning exercise (AM(ex)) would exhibit similar daytime BP (BP(day)) reduction in Dippers and Non-Dippers, (3) AM(ex) would exhibit greater 24 h BP (BP(24 h)) reduction than PM(ex) in Dippers, and (4) AM(ex) and PM(ex) would exhibit similar BP(24 h) reduction in Non-Dippers. BP responses to AM(ex) (0600-0800 h; 30 min at 50% VO(2peak)) and PM(ex) (1700-1900 h) were compared to each control day in a randomized design. Systolic (S) and diastolic (D) BP were averaged for BP(24 h), BP(day), and BP(night). A two-way ANOVA (dipping X time of exercise) using BP reduction with repeated measures were performed at P<0.05. FINDINGS: (1) Non-Dippers respond to exercise despite of TOD for exercise, (2) PM(ex) exhibited a greater SBP(night) reduction in Non-Dippers than Dippers, (3) AM(ex) exhibited similar SBP(day) reductions in Dippers and Non-Dippers, and (4) AM(ex) and PM(ex) exhibited similar SBP(24 h) reduction in Dippers and Non-Dippers. Dippers and Non-Dippers respond differently to TOD for exercise. The duration of the BP reduction persists up to 24 h after exercise.

Reproducibility of postexercise ambulatory blood pressure in Stage I hypertension.

The accuracy and reproducibility of ambulatory blood pressure monitoring used in intervention and treatment studies is essential to assure the desired health outcomes. The reproducibility of ambulatory variables in pharmacological studies has been reported, however, the reproducibility of ambulatory blood pressure variables associated with exercise has not been reported. Thus, the purpose of this study was to investigate the reproducibility of the postexercise ambulatory blood pressure in Stage I hypertensive adults. It was hypothesized that the reproducibility of the ambulatory blood pressure variables would not be different following two corresponding exercise and control treatments. A total of 18 Stage I hypertensive adults (142.1+/-3.15/91.6+/-1.80 mmHg) performed four randomized, 24 h AmBP monitoring sessions: two following a 50 min treadmill walk (50% VO(2) peak) and two on control days. Variables measured were: (1) average systolic and diastolic pressures for 24 h, daytime (06:00-22:00 h) and night time (22:00-06:00 h) and (2) systolic and diastolic load for the same time periods. Both a nonsignificant paired t-test and an excellent intraclass correlation were used to define reproducibility of the variables between the 1st and 2nd exercise trials and between the 1st and 2nd control trials. Reproducibility was found for all the control variables except for nighttime diastolic load. Reproducibility was found for all the systolic and diastolic exercise variables. Ambulatory blood pressure measurements, including average systolic and diastolic blood pressures and systolic and diastolic loads for 24 h, daytime and night time periods are reproducible following exercise.

Prospective evaluation of HDL cholesterol changes after diet and physical conditioning programs for patients with type II diabetes mellitus.

High-density lipoprotein (HDL) cholesterol is known to be low in patients with diabetes mellitus. Low HDL levels are correlated with premature cardiovascular mortality in several major epidemiologic studies and many investigators believe increases in HDL cholesterol may reduce the risk of coronary heart disease. We evaluated dietary and exercise interventions in relation to HDL cholesterol in patients with type II diabetes mellitus. Sixty-five volunteers were randomly assigned to one of four experimental conditions: diet, exercise, diet plus exercise, or education control. Three months after entering the program, those exposed to the dietary intervention had significant increases in HDL cholesterol. HDL increases for the other two treatment groups did not differ significantly from the education control.

Major mineral concentrations in human milk do not change after maximal exercise testing.

Fourteen healthy, lactating women (aged 25-38 y and between 2 and 8 mo postpartum) participated in both a maximal graded exercise test and a 30-min rest period to determine the influence of exercise on the concentration of selected milk minerals and electrolytes. Treatment order was randomized and treatments were conducted on different days. Milk was expressed before treatment and at 10, 30, and 60 min postexercise or after the rest period. Milk was wet-ashed by using nitric and sulfuric acids. Aliquots were analyzed for total phosphorus concentration by colorimetric assay and for calcium, magnesium, sodium, and potassium by inductively coupled plasma atomic emission spectrophotometry. Baseline mineral concentrations were not significantly different (P>0.05). Repeated expression of milk at 10, 30, and 60 min did not show significantly altered mineral concentrations (P>0.05). Interwoman variation was responsible for most of the variation in mineral concentrations. A portion of this may be explained by the variation in stage of lactation, which is known to affect mineral composition. Stage of lactation was inversely correlated with concentration of calcium, total phosphorus, magnesium, and sodium (P<0.05). In conclusion, maximal exercise did not alter concentrations of phosphorus, calcium, magnesium, potassium, or sodium in milk. Thus, with respect to mineral concentrations in milk, there is no contraindication for exercise during lactation.

Infant acceptance of postexercise breast milk.

The purpose of this study was to observe the infant acceptance of postexercise breast milk. Twenty-six lactating postpartum women exercised to maximum (maximum oxygen consumption = 35.1 +/- 9.2 [SD] mL min-1 kg-1) on a treadmill. Breast milk was collected via self-expression at rest before exercise and at 10 and 30 minutes postexercise and analyzed for lactic acid by enzymatic methods. Following exercise, infants were presented with their mothers' pre-exercise and postexercise milk in a double-blind design. The mother rated the infant's acceptance of the milk samples. There was a significant difference in acceptance of pre-exercise and postexercise milk as analyzed by analysis of variance. Maximal exercise resulted in a significant increase in lactic acid concentration in breast milk that may be high enough to affect the taste of the milk. The decreased acceptance of postexercise milk was associated with increased lactic acid concentration. Suggestions to circumvent the decreased acceptance are offered.

A comparison of 24-h average blood pressures and blood pressure load following exercise.

Although the use of 24-h ambulatory blood pressure monitoring has been recommended in the study of blood pressure and exercise, consistent results have not been found for average 24-h systolic or diastolic blood pressures. Systolic load and diastolic load (the percentage of pressures >140/90 mm Hg during daytime hours and >120/80 mm Hg during sleep) have recently been identified as an important variable, but has had limited use with exercise. The purpose of this study was to compare the average systolic and diastolic pressures to systolic and diastolic loads from 24-h data recorded after a 50-min treadmill walk at 50% VO2max to data from a nonexercise control day. Subjects were 36 normotensive (116.9 +/- 10.7/77.0 +/- 8.9 mm Hg) and 25 hypertensive (141.0 +/- 13.7/96.6 +/- 9.0 mm Hg) adults. No significant differences were found for systolic and diastolic pressures or loads between the control and exercise days for normotensives. Even though no significant changes were found for any of the average systolic and diastolic pressures between the control and exercise days for the hypertensives, significant reductions were found in systolic load for 24-h (-25.7%), day (6 AM to 10 PM, -23.1%), work (6 AM to 5 PM, -22.9%), and leisure (5 PM to 10 PM, -26.7%) periods; and in diastolic load for the work (-22.5%) period. Thus, the measurement of systolic and diastolic load may be more sensitive than average systolic and diastolic blood pressures for the detection of 24-h ambulatory blood pressure changes with exercise in borderline hypertension.

The magnitude and duration of ambulatory blood pressure reduction following acute exercise.

The purpose of this study was to observe the magnitude and duration of the ambulatory blood pressure (BP) reduction following exercise and to identify the peak intervals of BP reduction throughout the 24-h diurnal period. Subjects were 25 normo- (N = 116.7/ 78.2+/-10.0/7.2 mm Hg) and 21 hypertensive (H = 140.8/96.9+/-13.9/9.6 mm Hg) adults. Twenty-four hour ambulatory blood pressures (SBP = systolic and DBP = diastolic) were recorded following exercise (E = 50 min @ 50% VO2 max) and during a non-exercise control day (C). The 24-h pressures were compared between the E and C days for (1) duration and magnitude of the BP reduction following exercise, and for (2) the time of day for the diurnal patterns to exhibit reductions in BP. No BP differences were found for N between E and C days. Significant reductions in BP were found for 24-h average SBP (decrease 6.8 mm Hg) and DBP (decrease 4.1 mm Hg), daytime (06.00-22.00 hrs) SBP (decrease 6.9 mm Hg) and DBP (decrease 3.3 mm Hg), and sleep (22.00-06.00) SBP (decrease 5.1 mm Hg) and DBP (decrease 4.4 mm Hg) for H subjects only. H also demonstrated an 11 h reduction in SBP (chi = decrease 8.3+/-2.2 mm Hg) and 4h reduction in DBP (chi = decrease 6.0+/-1.7 mm Hg) following exercise. For the diurnal variation, the peak interval of reduction in SBP (chi = 17.0+/-2.6 mm Hg) was for 11 h; from 11.00-21.00 hrs. For DBP, a significant reduction (chi = decrease 5.7+/-0.7 mm Hg) was found for 5 h; from 11.00-15.00 h. Thus, exercise reduces both systolic and diastolic BP for a significant length of time postexercise as well as reduces pressures during the time of day that typically exhibits higher diurnal pressures.

Dietary fat, sugar, and fiber predict body fat content.

OBJECTIVE: This study was conducted to determine the relationships among the specific components of dietary fat and carbohydrate and body fatness in lean and obese adults. DESIGN: Body composition determination was performed on each subject by hydrostatic weighing at residual volume. Subsequently, the individual components of dietary fat and carbohydrate were examined relative to body fatness using a 3-day food diary and a food frequency questionnaire. SUBJECTS: Subjects were 23 lean (11.1 +/- 2.9% body fat) men, 23 obese (29.2 +/- 3.8% body fat) men, 17 lean (16.7 +/- 3.3% body fat) women, and 15 obese (42.7 +/- 3.9% body fat) women who volunteered for free diet and body composition analyses. Inclusion criteria were 15% body fat for lean men, 25% for obese men, 20% for lean women, and 35% for obese women. STATISTICAL ANALYSIS PERFORMED: Group comparisons for dietary variables were made with a multivariate analysis of variance. RESULTS: No differences were found between lean and obese subjects for energy intake or total sugar intake, but obese subjects derived a greater portion of their energy from fat (33.1 +/- 2.6% and 36.3 +/- 2.3% for obese men and women, respectively, vs 29.1 +/- 1.3% and 29.6 +/- 2.0%, lean men and women, respectively). Percent of fat intake for saturated, monounsaturated, and polyunsaturated fats was not different among groups. Obese subjects derived a greater percentage of their sugar intake from added sugars than lean subjects (38.0 +/- 3.5% vs 25.2 +/- 2.0%, respectively, for men; 47.9 +/- 8.0% vs 31.4 +/- 3.4%, respectively, for women). Dietary fiber was lower for obese men (20.9 +/- 1.8 g) and women (15.7 +/- 1.1 g) than for lean men (27.0 +/- 1.8 g) and women (22.7 +/- 2.1 g). APPLICATIONS/CONCLUSIONS: Obesity is maintained primarily by a diet that is high in fat and added sugar and relatively low in fiber. Alterations in diet composition rather than energy intake may be a weight control strategy for overweight adults.

Derivation of prediction equations for RV in overweight men and women.

PURPOSE: The purpose of this research was to derive and compare regression equations for predicting residual volume (RV) in overweight and normal weight adults. METHODS: RV was determined on land, in 311 men and women, following an overnight fast, using the nitrogen-dilution technique. Subjects were then weighed underwater at RV; 5-10 underwater weights were recorded; and the heaviest 3 measurements were averaged as the underwater weight. Percent body fat was calculated using the Siri equation. Group analyses were performed on overweight men (N = 59, body fat > 25%) and women (N = 126, body fat > 30%) compared with normal weight men (N = 68, body fat < or = 25%) and women (N = 58, body fat < or = 30%). A stepwise regression was performed for each group using the Systat Statistical Package (Evanston, IL). RESULTS: When RV was regressed on sex, age (yr), body weight (kg), and height (cm), sex was not found to be a significant predictor variable for RV. Subsequent regressions revealed that prediction equations for the overweight (RV = 0.0277 AGE + 0.0048 WT + 0.0138 HT - 2.3967, F = 44.0, P < 0.0000, SEE = 0.403) were different from those generated for normal weight men and women (RV = 0.0275 AGE + 0.0189 HT - 2.6139, F = 58.6, P < 0.0000, SEE = 0.405). Similar equations were obtained when a cross validation was performed on a separate sample of normal weight (N = 31) and overweight (N = 46) men and women. CONCLUSION: These data suggest that prediction equations for RV are separate and distinct for the overweight and normal weight populations.

Predicting max HR and the HR-VO2 relationship for exercise prescription in obesity.

This research derived regression equations for predicting maximal heart rate (MHR) and examined the relationship between relative oxygen consumption (VO2) and heart rate (HR) in obese (N = 86, body fat > 30%, hydrostatic weighing) compared with normal-weight (N = 51, body fat < or = 30%) adults. Simultaneous measurements of HR and VO2 were recorded at rest and every minute during a maximal graded exercise test. When MHR was regressed on age, two distinct equations for the obese and normalweights were generated. The relationship between %MHR and %max VO2 was similar between groups (r = 0.83, obese; r = 0.87 normalweights). Likewise, when %max VO2 was regressed on %max heart rate range similar equations were derived fro the obese (r = 0.81) and normalweights (r = 0.84). Correlation between Karvonen's predicted HR at a submaximal VO2 and the true HR at that VO2 was 0.88, regardless of adiposity. These data indicate that when predicting MHR in normalweights the equation 220-Age can be used, but for obese individuals the equation 200-0.5 x Age is more accurate; each having 12 as a standard error of estimate. Once MHR is determined, either the straight percentage technique or Karvonen's method would be appropriate for prescribing exercise intensity for both populations.