Higher extracellular fluid volume in women is concealed by scaling to body surface area

Abstract

Objective. The objective was to assess body surface area (BSA) for scaling extracellular fluid volume (ECV) in comparison with estimated lean body mass (LBM) and total body water (TBW) across a range of body mass indices (BMI). Methods. This was a multi-centre study from 15 centres that submitted raw data from routine measurement of GFR in potential kidney transplant donors. There were 819 men and 1059 women in total. ECV was calculated from slope-intercept and slope-only measurements of GFR. ECV was scaled using two methods: Firstly, division of ECV by the scaling variable (ratio method), and secondly the regression method of Turner and Reilly. Subjects were placed into five BMI groups: < 20, 20–24.9, 25–29.9, 30–34.9, and 35 + kg/m². LBM and TBW were estimated from previously published, gender-specific prediction equations. Results. Ratio and regression scaling gave almost identical results. ECV scaled to BSA by either method was higher in men in all BMI groups but ECV scaled to LBM and TBW was higher in women. There was, however, little difference between men and women in respect to ECV per unit weight in any BMI group, even though women have 10% more adipose tissue. The relations between TBW and BSA and between LBM and BSA, but not between LBM and TBW, were different between men and women. Conclusion. Lean tissue in women contains more extracellular water than in men, a difference that is obscured by scaling to BSA. The likely problem with BSA is its insensitivity to body composition.     

Trends in the prevalence and ratio of diagnosed to undiagnosed diabetes according to obesity levels in the U.S

OBJECTIVE: To examine trends in the prevalence of diagnosed and undiagnosed diabetes and the proportion of total cases previously diagnosed, according to obesity status in the U.S. over the past 40 years. RESEARCH DESIGN AND METHODS: We assembled data from five consecutive cross-sectional national surveys: National Health Examination Survey I (1960-1962), National Health and Nutrition Examination Survey (NHANES) I (1971-1974), NHANES II (1976-1980), NHANES III (1988-1994), and NHANES 1999-2000. Diagnosed diabetes was ascertained, and height and weight were measured in adults aged 20-74 years in all surveys. In NHANES II, NHANES III, and NHANES 1999-2000, a fasting glucose level > or =126 mg/dl was used to identify cases among individuals not reporting diabetes. Design-based analyses and Bayesian models estimate the probability that prevalence of diabetes increased within four BMI groups (<25, 25-29, 30-34, and > or =35 kg/m2). RESULTS: In the U.S. population aged 20-74 years between 1976-1980 and 1999-2000, significant increases in the prevalence of diagnosed diabetes (3.3-5.8%, probability >99.9%) were accompanied by nonsignificant increases in undiagnosed diabetes (2.0-2.4%, 66.6%). This resulted in an increase in total diabetes (5.3-8.2%, >99.9%) and a modest nonsignificant increase in the proportion of cases that were diagnosed (62-70%, 62.4%). However, these trends varied considerably by BMI level. In individuals with BMI > or =35 kg/m2, diagnosed diabetes increased markedly (from 4.9% in 1960, to 8.6% during 1976-1980, to 15.1% in 1999-2000; probability >99.9%), whereas undiagnosed diabetes declined considerably (12.5% during 1976-1980 to 3.2% in 1999-2000, probability of increase 4.5%) Therefore, the proportion of total diabetes cases that were diagnosed increased from 41 to 83% (probability 99.9%) among individuals with BMI > or =35 kg/m2. By comparison, changes in prevalence within BMI strata <35 kg/m2 were modest and there was no increase in the percent of total cases that were diagnosed. CONCLUSIONS: National surveys over the last several decades have found large increases in diagnosed diabetes, particularly in overweight and obese individuals, but this has been accompanied by large decreases in undiagnosed diabetes only among individuals with BMI > or =35 kg/m2. This suggests that improvements in diabetes awareness and detection are most prominent among this subgroup.     

A Comparison of Factors Associated with Running-Related Injuries between Adult and Adolescent Runners

BackgroundThere are multiple personal and environmental factors that influence the risk of developing running-related injuries (RRIs). However, it is unclear how these key clinical factors differ between adult and adolescent runners.PurposeThe purpose of this study was to compare anthropometric, training, and self-reported outcomes among adult and adolescent runners with and without lower extremity musculoskeletal RRIs.Study DesignCross-sectional study.MethodsQuestionnaire responses and clinical assessment data were extracted from 38 adult runners (F: 25, M: 13; median age: 23 [range 18-36]) and 91 adolescent runners (F: 56, M: 35; median age: 15 [range 14-16]) who underwent a physical injury prevention evaluation at a hospital-affiliated sports injury prevention center between 2013 and 2021. Participants were sub-grouped into those with (adults: 25; adolescents: 38) and those without (adults: 13; adolescents: 53) a history of self-reported RRIs based on questionnaire responses. Multivariate analyses of covariance (MANCOVA) covarying for gender were conducted to compare outcomes across groups.ResultsAdult runners had lower Functional Movement Screen™ (FMS™) scores (mean differences [MD]: -1.4, p=0.01), were more likely to report intentional weight-loss to improve athletic performance (% difference: 33.0%; p:<.001), and more frequently included resistance training into their training routines (% difference: 21.0%, p=0.01) compared to adolescents. Those with a history of RRIs were more likely to report intentional weight-loss compared to uninjured runners (% difference: 21.3; p=0.02) and had shorter single leg bridge durations than those without RRIs (RRI: 57.9±30, uninjured: 72.0±44, p=0.01).ConclusionThe findings indicate that addressing aspects of biomechanics identified by the FMS™ and behaviors of weight loss as an effort to improve performance may represent targets for the prevention of RRIs for adult and adolescent runners, given the association with history of RRIs.Level of Evidence3     

Association between patients' body mass index and emergency department wait times: A multicenter observational cohort investigation by the reducing disparities increasing equity in emergency medicine (REDEEM) study group

ObjectiveNumerous studies have demonstrated evidence of obesity bias in healthcare settings, however, little is known about obesity bias in the Emergency Department (ED). The objective of this study was to investigate obesity bias in an ED setting by assessing the association between body mass index (BMI) and door-to-room (DTR) or door-to-provider (DTP) times among ED patients.MethodsWe conducted an observational cohort study of all adult patient (age ≥ 18 years of age) visits to 21 Mayo Clinic and Mayo Clinic Health System EDs between November 1, 2018 and March 31, 2020. We compared DTR and DTP times based on BMI category.ResultsWe found that median DTR and DTP times for adults with class 3 obesity are significantly shorter than patients in the normal weight category. For men with class 3 obesity, median DTR and DTP times were 7.5% and 5.4% shorter than men in the normal weight category. Relative to women in the normal weight category, the median DTR and DTP times were 4.6% and 3.8% faster for women in obesity class 1, 4.9% and 5.1% faster for women in obesity class 2, and DTR was 4.4% faster for women in obesity class 3. These percentage differences translated to slightly shorter wait times of 0.4–1.2 min compared to median wait times for patients with normal BMI.ConclusionWe did not find evidence of longer wait times experienced by people with obesity. Rather, patients with obesity often experienced wait times that were shorter than patients of normal weight.     

Evaluating Employee Health Risks Due to Hypertension and Obesity: Self-Testing Workplace Health Stations

Abstract

Background: We evaluated employee health risks due to hypertension, pre-hypertension, overweight, and obesity through the use of self-testing workplace health stations that measure blood pressure (BP) and weight. Methods: We analyzed BP and weight data from the first 18 months after the installation of health stations in the offices of a financial services company with approximately 20 000 employees in 13 US workplace locations. Results: Data showed that 21.7% of the employees voluntarily used a health station at least once to measure BP or weight during the first 18 months. Health station usage ranged from a high of 51.8% to a low of 5.3% at the 13 workplace locations. Among health station users, 52.5% used a health station more than once. Health station users used the health stations an average of 4.2 times (median, 2 times). Among health station users, 95.6% measured BP, 92.2% measured weight, and 87.8% measured both BP and weight. Initial BP results were: hypertension 26.7%, prehypertension 40.3%, and normal BP 32.9%. The initial body mass index (BMI) results were: obese 38%, overweight 34.7%, normal weight 25.3%, and underweight 2%. Employees with hypertension on the initial reading used the health stations more frequently than employees with pre-hypertension or normal BP. Employees with an obese BMI result on the initial reading used the health stations more frequently than employees with an overweight or normal BMI result. Many employees reduced their health risks due to hypertension, pre-hypertension, overweight, or obesity, although the health risks of many other employees were unchanged or increased. Conclusions: Self-testing workplace health stations that measure BP and weight provide employees with information about their health risks due to hypertension, pre-hypertension, overweight, and obesity. Self-testing workplace health stations can also be used to identify at-risk employees who may benefit from health and wellness programs.     

Insomnia and physical activity in adults with prediabetes

This secondary analysis study examines the relationship between physical activity and symptoms of insomnia among adults with prediabetes (N = 958) from the 2005-2006 National Health and Nutrition Examination Survey (NHANES). The sample of participants were generally obese, middle-aged, and racially diverse. NHANES questions included symptoms of insomnia, sleep duration, and sleep latency. Body mass index (BMI) was calculated from measured height and weight; at least 2 days of ActiGraph activity monitor data determined mean steps walked. Men walked more steps than women; however, women had more insomnia symptoms. There were significant associations between insomnia symptoms and increased sleep latency and decreased sleep duration. Multiple regression analysis showed that younger age, lower BMI, higher self-rated health, high school education, and fewer insomnia symptoms were significantly related to increased steps walked. The findings indicate that insomnia in adults with prediabetes may be a barrier to their adapting an active lifestyle.     

Serum alanine aminotransferase is correlated with hematocrit in healthy human subjects

Abstract

Background. Serum alanine aminotransferase (ALT) activity is a widely-used surrogate marker for liver injury. However, mild elevation of serum ALT is frequently observed in apparently healthy individuals, making it sometimes challenging to interpret whether this laboratory abnormality is medically benign or serious. To obtain a better understanding of the factors influencing ALT levels, we examined the relation between ALT and a number of anthropometric and biochemistry measurements in humans. Methods. We assessed the associations of ALT with hematocrit (HCT) in 1,200 apparently healthy adults from an Amish population. Multivariate analyses were carried out to determine whether observed associations were independent of other factors known to modulate ALT and HCT, including body mass index (BMI) and sex. The correlation detected in the Amish was then replicated in an independent population sample (N = 9,842) from the National Health and Nutrition Examination Survey (NHANES) III. Results. ALT levels were positively correlated with HCT (r = 0.33, p < 0.0001) in both Amish and NHANES III. The magnitude of association was unchanged after adjustment for BMI, but was reduced by age/sex adjustment to r = 0.18 (p < 0.0001) and r = 0.17 (p < 0.0001) in the Amish and NHANES populations, respectively. HCT accounts for about 3% of the population variation in ALT, which is smaller than the contributions of gender and BMI, but larger than individual blood pressure and cholesterol components. Conclusions. We observed a correlation between ALT and HCT, suggesting that HCT may be a newly identified modulator of ALT in humans.     

Prevalence of Apparent Treatment-Resistant Hypertension in the United States According to the 2017 High Blood Pressure Guideline

ObjectiveTo evaluate the prevalence of apparent treatment-resistant hypertension (aTR-hypertension) in US adults with treated hypertension by using the nationally representative National Health and Nutrition Examination Survey (NHANES).Patients and MethodsNonpregnant US adults older than 20 years with a self-reported history of treated hypertension who had blood pressure measured in NHANES cycles 2007 to 2014 were included in this study. Study participants were stratified into 4 groups according to average blood pressure and antihypertensive medication use: well-controlled hypertension, undertreated hypertension, aTR-hypertension by the 2017 guideline, and aTR-hypertension by the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guideline. National Health and Nutrition Examination Survey sample weights were used to estimate the national prevalence.ResultsFrom 2007 to 2014, 5512 participants with treated hypertension representing 46.7 million people nationally were included. Compared with JNC 7 guideline criteria, application of the 2017 high blood pressure guideline criteria increased the prevalence of aTR-hypertension in US adults with treated hypertension from 12.0% to 15.95%, identifying an additional 1.85 million individuals with aTR-hypertension nationally. Individuals newly reclassified as having aTR-hypertension were younger. However, the prevalence of thiazide diuretic use remained less than 70%, and that of mineralocorticoid antagonist use remained less than 10% regardless of the guideline definition.ConclusionOn the basis of the 2017 high blood pressure guideline, the prevalence of aTR-hypertension is 15.95% in US adults with treated hypertension. This represents an absolute increase of 4% (1.85 million additional individuals nationally) compared with the JNC 7 guideline definition, with a consistent increase across all subpopulations with treated hypertension.     

Weight control practices and disordered eating behaviors among adolescent females and males with type 1 diabetes: associations with sociodemographics,weight concerns,familial factors,and metabolic outcomes

OBJECTIVE: This study examines the prevalence of specific weight control practices/disordered eating behaviors and associations with sociodemographic characteristics, BMI and weight perceptions, family functioning, and metabolic control among adolescent females and males with type 1 diabetes. RESEARCH DESIGN AND METHODS: The study population included 70 adolescent females and 73 adolescent males with type 1 diabetes who completed the AHEAD (Assessing Health and Eating among Adolescents with Diabetes) survey. Data on BMI and glycosylated hemoglobin (HbA(1c)) were drawn from medical records. RESULTS: Unhealthy weight control practices were reported by 37.9% of the females and by 15.9% of the males. Among the females, 10.3% reported skipping insulin and 7.4% reported taking less insulin to control their weight. Only one male reported doing either of these behaviors. Weight control/disordered eating behaviors were not associated with age, parental level of education, family structure, or race/ethnicity. Higher levels of weight dissatisfaction tended to be associated with unhealthy weight control/disordered eating; associations with BMI were inconsistent. Family cohesion was negatively associated with disordered eating among females (r = -0.52; P < 0.001) and males (r = -0.41; P < 0.001), but correlations with other measures of family environment (control, independence, and responsibility for diabetes management) were not significant. Correlations between disordered eating and HbA(1c) levels were significant among females (r = 0.33; P < 0.01) and males (r = 0.26; P < 0.05). CONCLUSIONS: Special attention is needed for youth with weight concerns and those from less cohesive families to assist in the development of healthy diabetes management behaviors.     

The relationship between shift work and body mass index among Canadian nurses

AimThe aim of this study was to examine the relationship between shift schedule and body mass index (BMI) among a sample of Canadian Nurses.BackgroundHigher BMI values have been reported for employees working non-standard shifts compared to those working a regular daytime schedule. Little is known about the pathways through which shift work is associated with higher BMI.MethodsThis study was a secondary analysis of a sample from National Survey on the Work and Health of Nurses (N = 9291).ResultsWe found a small, but statistically significant, difference in BMI scores across shift schedule categories with higher BMI scores reported among female nurses working night or mixed shift schedules, compared with those working a regular daytime schedule. Adjustment for working conditions and employer supported facilities did not attenuate the association between shift work and BMI scores.ConclusionsThe potential public health importance of this relationship requires further investigation given the small, but statistically significant, differences observed in this sample.     

The relationship of body mass index to diabetes mellitus, hypertension and dyslipidaemia: comparison of data from two national surveys

The objectives of this study were to explore the relation between body mass index (BMI) and prevalence of diabetes mellitus, hypertension and dyslipidaemia; examine BMI distributions among patients with these conditions; and compare results from two national surveys. The Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD) 2004 screening questionnaire (mailed survey) and the National Health and Nutrition Examination Surveys (NHANES) 1999-2002 (interview, clinical and laboratory data) were conducted in nationally representative samples>or=18 years old. Responses were received from 127,420 of 200,000 households (64%, representing 211,097 adults) for SHIELD, and 4257 participants for NHANES. Prevalence of diabetes mellitus, hypertension and dyslipidaemia was estimated within BMI categories, as was distribution of BMI levels among individuals with these diseases. Mean BMI was 27.8 kg/m2 for SHIELD and 27.9 kg/m2 for NHANES. Increased BMI was associated with increased prevalence of diabetes mellitus, hypertension and dyslipidaemia in both studies (p<0.001). For each condition, approximately [corrected] 75% or more [corrected] of patients had BMI>or=25 kg/m2. Estimated prevalence of diabetes mellitus and hypertension was similar in both studies, while dyslipidaemia was substantially higher in NHANES than SHIELD. In both studies, prevalence of diabetes mellitus, hypertension and dyslipidaemia occurred across all ranges of BMI, but increased with higher BMI. However, not all overweight or obese patients had these metabolic diseases and not all with these conditions were overweight or obese. Except for dyslipidaemia prevalence, SHIELD was comparable with NHANES. Consumer panel surveys may be an alternative method to collect data on the relationship of BMI and metabolic diseases.     

Rehabilitation Length of Stay,Body Mass Index,and Functional Improvement Among Adults With Traumatic Spinal Cord Injury

ObjectiveTo examine the modifying effect of body mass index (BMI) on the association between rehabilitation length of stay (LOS), severity of injury, and motor FIM (mFIM) improvement in patients with traumatic spinal cord injury (TSCI).DesignRetrospective cohort study.SettingSeventeen SCI Model Systems (SCIMS) centers in the United States.ParticipantsA total of 3413 patients (N=3413) who had a TSCI were admitted to an SCIMS between October 2011 and August 2018.InterventionsNot applicable.Main Outcome MeasuresThe mFIM (12 items) improvement by discharge. Four rehabilitation LOS groups split by quartiles were created for each neurologic severity of injury group (C1-C4 level with American Spinal Injury Association Impairment Scale [AIS] ABC, C5-C8 AIS ABC, T1-S3 AIS ABC, AIS DE). The interrelationship among rehabilitation LOS, BMI, and mFIM improvement were examined using multivariate linear regressions. A stratified analysis was performed to examine the association between rehabilitation LOS and mFIM improvement by BMI status (underweight or normal weight, overweight, obesity) and neurologic groups.ResultsA total of 1099 (32.2%) and 821 (24.1%) patients were overweight and had obesity, respectively. Patients with obesity had less improvement in mFIM than those who were underweight or normal weight (unit of mFIM improvement, ?3.71). After stratifying by BMI status, among patients with obesity, those with the longest rehabilitation LOS showed greater improvement in mFIM than those in the shortest LOS (unit of mFIM improvement=4.78).ConclusionsLonger inpatient rehabilitation LOS may benefit patients with TSCI by increasing mFIM improvement by discharge. Obesity is negatively associated with mFIM improvement.     

Obesity and the clinical use of serum GGT activity as a marker of heavy drinking

Objective. Gamma‐glutamyl transferase (GGT) is a widely used clinical marker of alcohol abuse. However, although obesity may also elevate serum GGT activities, the effects of overweight on the interpretation of GGT testing have remained poorly defined. Material and methods. GGT activities from 1147 moderate drinkers and 449 abstainers who were classified according to body mass index (BMI) were compared with those of 208 heavy drinkers admitted for detoxification. Results. GGT upper normal limits, defined based on normal weight abstainers (men 53?U/L; women 45?U/L) were lower than those based on moderate drinkers (men 68?U/L; women 50?U/L). The relative increases in GGT activities in male moderate drinkers with overweight (54%) or obesity (125%) exceeded the corresponding changes found in women (25% and 75%, respectively). The BMI‐dependent variation on the sensitivity of GGT for correctly classifying heavy drinkers ranged from 29% to 67%. The rates of false‐positive values in the subgroups from low to high BMI varied from 0% to 27%, respectively. Conclusions. The data indicate that the diagnostic value of serum GGT testing could be improved by using reference data derived from databases of abstainers with normal weight or BMI‐based categorization of reference ranges.     

Prevalence and trends of a metabolic syndrome phenotype among u.s. Adolescents, 1999-2000

OBJECTIVE: To determine the prevalence of a metabolic syndrome phenotype among U.S. adolescents using the most recent national data and to examine trends in metabolic syndrome prevalence. RESEARCH DESIGN AND METHODS: Analysis of data on 991 adolescents (aged 12-19 years) who had fasted for at least 6 h, from the National Health and Nutrition Examination Survey (NHANES 1999-2000). The metabolic syndrome was determined using the National Cholesterol Education Program (Adult Treatment Panel III) definition modified for age. RESULTS: The overall prevalence of a metabolic syndrome phenotype among U.S. adolescents increased from 4.2% in NHANES III (1988-1992) to 6.4% in NHANES 1999-2000 (P < 0.001). The syndrome was more prevalent (P < 0.01) in male than female adolescents (9.1 vs. 3.7%) and was found in 32.1% of overweight adolescents (BMI > or = 95th percentile for age and sex), compared with 7.1% of adolescents at risk for overweight (BMI between 85th and 95th percentiles) (P < 0.001). Based on population-weighted estimates, > 2 million U.S. adolescents currently have a metabolic syndrome phenotype. CONCLUSIONS: The prevalence of a metabolic syndrome phenotype has increased significantly over the past decade among U.S. adolescents and is particularly prevalent (> 30%) in overweight adolescents. These findings have important implications for public health because of the well-known health risks associated with the metabolic syndrome in adults.     

Cardiovascular Health Metrics and Accelerometer-Measured Physical Activity Levels: National Health and Nutrition Examination Survey, 2003-2006

ObjectiveTo determine whether relationships exist between accelerometer-measured moderate-to-vigorous physical activity (MVPA) and other cardiovascular (CV) health metrics in a large sample.Patients and MethodsData from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) collected from January 1, 2003, through December 31, 2006, were used. Overall, 3454 nonpregnant adults 20 years or older who fasted for 6 hours or longer, with valid accelerometer data and with CV health metrics, were included in the study. Blood pressure (BP), body mass index (BMI), smoking status, diet, fasting plasma glucose level, and total cholesterol level were defined as ideal, intermediate, and poor on the basis of American Heart Association criteria. Results were weighted to account for sampling design, oversampling, and nonresponse.ResultsSignificant increasing linear trends in mean daily MVPA were observed across CV health levels for BMI, BP, and fasting plasma glucose (P<.001). Those with a poor BMI and BP had significantly lower mean daily MVPA than those with intermediate and ideal BMIs and BPs (all P<.001). In addition, individuals with an intermediate fasting plasma glucose level had significantly lower mean daily MVPA than individuals at the ideal levels (P<.001). No significant linear trends were observed for cholesterol, smoking, and diet. A significant linear trend was observed for mean daily MVPA and the overall number of other CV health metrics (P<.001).ConclusionObjectively measured MVPA was related to other CV health metrics in this large sample. These results support the inclusion of physical activity in the overall definition of ideal CV health.     

Trends in Obesity Prevalence among US Older Adults in the Last Two Years of Life, 1998–2018

ContextThe prevalence of obesity has grown in the US over the decades. The temporal trends of body mass index categories in the last two years of life are poorly understood.ObjectivesTo describe the trends in body mass categories in the last two years of life over the past two decades controlling for other demographic changes.MethodsWe performed a cross-sectional study of prospectively collected survey data from the nationally representative Health and Retirement Study (HRS) among decedents who died between 1998 and 2018. We categorized BMI into five categories and calculated the proportion of decedents with each BMI category during each four epochs (1998–2003, 2004–2008, 2009–2013, 2014–2018). We examined trends in regression models with survey wave groupings modeled as an orthogonal polynomial and adjusted for factors commonly associated with BMI: sex, age, race, ethnicity, education, and tobacco use.ResultsThe analytic cohort included 14,797 decedents. From 1998–2003 to 2014–2018 time periods, those categorized as having mild-to-moderate obesity in the last two years of life increased from 12.4% to 14.8% (linear trend P < 0.001), a 19% increase. Severe obesity increased from 1.9% to 4.3%, a 126% increase (linear trend P < 0.001). Underweight decreased from 9.9% to 5.9%, a 40% decrease (linear trend P < 0.001), adjusted for demographic factors. Adjusted quadratic temporal trends for BMI category were nonsignificant, except for in mild-to-moderate obesity.ConclusionSevere obesity has increased greatly while underweight has decreased. As obesity increases in the final years of life, it is critical to assess how the existing and future palliative services and end of life care system address body size and weight.     

Rest-Activity Rhythm Characteristics Associated With Depression Symptoms in Stroke Survivors

ObjectiveTo examine which 24-hour rest-activity rhythm (RAR) characteristics are associated with depression symptoms in stroke survivors.DesignCross-sectional observational study examining associations of RAR characteristics with the presence of depression symptoms adjusting for age, sex, race, and medical comorbidity.SettingCommunity setting.ParticipantsStroke survivors: (1) recruited locally (N women=35, N men=28) and (2) a nationally representative probability sample (the National Health and Nutrition Examination Survey [NHANES]; N women=156, N men=124).InterventionsNone.MeasurementsObjective RAR characteristics derived from accelerometer recordings including activity onset/offset times and non-parametric measures of RAR strength (relative amplitude), stability (interdaily stability), and fragmentation (intradaily variability). The presence of depression symptoms was categorized using Patient Health Questionnaire scores.ResultsIn both samples, the only RAR characteristic associated with depression symptoms was intradaily variability (fragmentation): local sample, odds ratio=1.96 [95% confidence interval=1.05-3.63]; NHANES sample, odds ratio=1.34, [95% confidence interval=1.01-1.78]). In the NHANES sample, which included both mild and moderate/severe depression, the association between 24-hour sleep-wake fragmentation and depression symptoms was driven by moderate-to-severe cases.ConclusionsStroke survivors with higher levels of RAR fragmentation were more likely to have depression symptoms in both samples. These findings have implications, given prior studies in general samples linking RAR fragmentation with future depression and dementia risk. Research is needed to establish the potential consequences, mechanisms, and modifiability of RAR fragmentation in stroke survivors.     

腰椎骨质密度与年龄、性别、体质参数及腹部脂肪的相关性

目的 探讨腰椎骨质密度(BMD)与年龄、性别、体质参数及腹部皮下脂肪(SAT)、内脏脂肪(VAT)的关系。方法 纳入健康志愿者或慢性腰腿痛患者111人(男56人,女55人),测量受检者身高、体质量及腰围,计算体质指数(BMI);采用定量CT(QCT)行腹部扫描,测量L3的BMD及相应层面腹部SAT与VAT含量。将男性与女性分别分为骨质疏松组、骨量减少组和骨量正常组,分别比较3组间年龄、性别、身高、体质量、BMI、腰围、SAT和VAT的差异,对BMD与存在显著性差异的指标进行相关性分析。结果 3组男性间除年龄的差异有统计学意义(P<0.05)外,身高、体质量、BMI、腰围、SAT及VAT的差异均无统计学意义(P均>0.05);男性BMD与年龄呈负相关(r=-0.680,P<0.05)。3组女性年龄、腰围及VAT的差异有统计学意义(P均<0.05),身高、体质量、BMI、SAT差异均无统计学意义(P均>0.05);女性BMD与年龄、腰围、VAT均呈负相关(r= -0.849、-0.412、-0.501,P均<0.05)。结论 男、女性腰椎BMD与年龄均呈明显负相关,与身高、体质量、BMI无明显相关性;男性腰椎BMD与腰围、SAT与VAT均无明显相关性,但女性腰椎BMD与腰围及VAT关系密切。