ABSTRACT
OBJECTIVE: Quadriceps muscle weakness is common in knee osteoarthritis (OA). While pain, disuse, and atrophy are commonly cited causes for muscle weakness in OA, emerging evidence suggests changes in muscle quality also occur. Alterations in muscle quality are not well understood, but likely include both cellular and morphologic adaptions. The purpose of this study was to conduct the first cellular-level analysis of the vastus lateralis in adults with moderate knee OA. METHODS: Vastus lateralis biopsies were obtained from 24 subjects with moderate knee OA and 15 healthy controls. Quadriceps strength, muscle fiber cross sectional area (CSA), fiber type distribution, extracellular matrix (ECM) content, satellite cell abundance, and profibrotic gene expression were assessed. RESULTS: Relative to controls, quadriceps strength was significantly lower in OA subjects (OA 62.23, 50.67-73.8 Nm vs 91.46, 75.91-107.0 Nm, P = 0.003) despite no difference in fiber CSA. OA subjects had significantly fewer Type I fibers (OA 41.51, 35.56-47.47% vs 53.07, 44.86-61.29%, P = 0.022) and more hybrid IIa/x fibers (OA 24.61, 20.61-28.61% vs 16.4, 11.60-21.20%, P = 0.009). Significantly greater ECM content, lower satellite cell density, and higher profibrotic gene expression was observed with OA, and muscle collagen content was inversely correlated to strength and satellite cell (SC) density. CONCLUSION: Lower quadriceps function with moderate OA may not result from fiber size impairments, but is associated with ECM expansion. Impaired satellite cell density, high profibrotic gene expression, and a slow-to-fast fiber type transition may contribute to reduced muscle quality in OA. These findings can help guide therapeutic interventions to enhance muscle function with OA.
Subject(s)
Extracellular Matrix/metabolism , Muscle Strength/physiology , Muscle Weakness/etiology , Osteoarthritis, Knee/diagnosis , Quadriceps Muscle/pathology , Satellite Cells, Skeletal Muscle/pathology , Aged , Biopsy , Cross-Sectional Studies , Extracellular Matrix/genetics , Female , Gene Expression Regulation , Humans , Male , Middle Aged , Muscle Weakness/metabolism , Muscle Weakness/physiopathology , Osteoarthritis, Knee/complications , Osteoarthritis, Knee/metabolism , Quadriceps Muscle/metabolism , Quadriceps Muscle/physiopathology , RNA/genetics , Satellite Cells, Skeletal Muscle/metabolismABSTRACT
BACKGROUND AND AIMS: Understanding contributions of lean and fat tissue to cardiovascular and non-cardiovascular mortality may help clarify areas of prevention in older adults. We aimed to define distributions of lean and fat tissue in older adults and their contributions to cause-specific mortality. METHODS AND RESULTS: A total of 1335 participants of the Cardiovascular Health Study (CHS) who underwent dual-energy x-ray absorptiometry (DEXA) scans were included. We used principal components analysis (PCA) to define two independent sources of variation in DEXA-derived body composition, corresponding to principal components composed of lean ("lean PC") and fat ("fat PC") tissue. We used Cox proportional hazards regression using these PCs to investigate the relationship between body composition with cardiovascular and non-cardiovascular mortality. Mean age was 76.2 ± 4.8 years (56% women) with mean body mass index 27.1 ± 4.4 kg/m2. A greater lean PC was associated with lower all-cause (HR = 0.91, 95% CI 0.84-0.98, P = 0.01) and cardiovascular mortality (HR = 0.84, 95% CI 0.74-0.95, P = 0.005). The lowest quartile of the fat PC (least adiposity) was associated with a greater hazard of all-cause mortality (HR = 1.24, 95% CI 1.04-1.48, P = 0.02) relative to fat PCs between the 25th-75th percentile, but the highest quartile did not have a significantly greater hazard (P = 0.70). CONCLUSION: Greater lean tissue mass is associated with improved cardiovascular and overall mortality in the elderly. The lowest levels of fat tissue mass are linked with adverse prognosis, but the highest levels show no significant mortality protection. Prevention efforts in the elderly frail may be best targeted toward improvements in lean muscle mass.
Subject(s)
Body Composition , Cardiovascular Diseases/mortality , Sarcopenia/mortality , Absorptiometry, Photon , Adiposity , Age Factors , Aged , Aged, 80 and over , Body Mass Index , Cardiovascular Diseases/physiopathology , Cardiovascular Diseases/prevention & control , Cause of Death , Comorbidity , Female , Geriatric Assessment , Humans , Male , Multivariate Analysis , Prevalence , Principal Component Analysis , Prognosis , Proportional Hazards Models , Prospective Studies , Protective Factors , Risk Assessment , Risk Factors , Sarcopenia/physiopathology , Sarcopenia/therapy , United States/epidemiologyABSTRACT
OBJECTIVE: To describe associations between total and regional body fat mass loss and reduction of systemic levels of inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6)) in obese, older adults with osteoarthritis (OA), undergoing intentional weight loss. DESIGN: Data come from a single-blind, 18-month, randomized controlled trial in adults (age: 65.6 ± 6.2; Body mass index (BMI): 33.6 ± 3.7) with knee OA. Participants were randomized to diet-induced weight loss plus exercise (D + E; n = 150), diet-induced weight loss-only (D; n = 149), or exercise-only (E; n = 151). Total body and region-specific (abdomen and thigh) fat mass were measured at baseline and 18 months. High-sensitivity CRP and IL-6 were measured at baseline, six and 18 months. Intervention effects were assessed using mixed models and associations between inflammation and adiposity were compared using logistic and mixed linear regression models. RESULTS: Intentional total body fat mass reduction was associated with significant reductions in log-adjusted CRP (ß = 0.06 (95% CI = 0.04, 0.08) mg/L) and IL-6 (ß = 0.02 (95% CI = 0.01, 0.04) pg/mL). Loss of abdominal fat volume was also associated with reduced inflammation, independent of total body fat mass; although models containing measures of total adiposity yielded the best fit. The odds of achieving clinically desirable levels of CRP (<3.0 mg/L) and IL-6 (<2.5 pg/mL) were 3.8 (95% CI = 1.6, 8.9) and 2.2 (95% CI = 1.1, 4.6), respectively, with 5% total weight and fat mass loss. CONCLUSIONS: Achievement of clinically desirable levels of CRP and IL-6 more than double with intentional 5% loss of total body weight and fat mass. Global, rather than regional, measures of adiposity are better predictors of change in inflammatory burden. CLINICAL TRIAL REGISTRATION NUMBER: NCT00381290.
Subject(s)
C-Reactive Protein/analysis , Interleukin-6/blood , Osteoarthritis, Knee/blood , Overweight/blood , Aged , Diet, Reducing , Exercise , Female , Humans , Male , Obesity/blood , Obesity/complications , Osteoarthritis, Knee/complications , Overweight/complications , Single-Blind Method , Weight LossABSTRACT
OBJECTIVE: To determine the effects of dietary-induced weight loss (D) and weight loss plus exercise (D + E) compared to exercise alone (E) on bone mineral density (BMD) in older adults with knee osteoarthritis (OA). DESIGN: Data come from 284 older (66.0 ± 6.2 years), overweight/obese (body mass index (BMI) 33.4 ± 3.7 kg/m2), adults with knee OA enrolled in the Intensive Diet and Exercise for Arthritis (IDEA) study. Participants were randomized to 18 months of walking and strength training (E; n = 95), dietary-induced weight loss targeting 10% of baseline weight (D; n = 88) or a combination of the two (D + E; n = 101). Body weight and composition (DXA), regional BMD, were obtained at baseline and 18 months. RESULTS: E, D, and D + E groups lost 1.3 ± 4.5 kg, 9.1 ± 8.6 kg and 10.4 ± 8.0 kg, respectively (P < 0.01). Significant treatment effects were observed for BMD in both hip and femoral neck regions, with the D and D + E groups showing similar relative losses compared to E (both P < 0.01). Despite reduced BMD, fewer overall participants had T-scores indicative of osteoporosis after intervention (9 at 18 months vs 10 at baseline). Within the D and D + E groups, changes in hip and femoral neck, but not spine, BMD correlated positively with changes in body weight (r = 0.21 and 0.54 respectively, both P ≤ 0.01). CONCLUSIONS: Weight loss via an intensive dietary intervention, with or without exercise, results in bone loss at the hip and femoral neck in overweight and obese, older adults with OA. Although the exercise intervention did not attenuate weight loss-associated reductions in BMD, classification of osteoporosis and osteopenia remained unchanged. CLINICAL TRIAL REGISTRATION NUMBER: NCT00381290.
Subject(s)
Bone Density/physiology , Obesity/diet therapy , Obesity/rehabilitation , Osteoarthritis, Knee/therapy , Weight Loss/physiology , Age Factors , Aged , Aged, 80 and over , Analysis of Variance , Body Mass Index , Combined Modality Therapy , Confidence Intervals , Diet, Reducing/methods , Exercise Therapy/methods , Female , Follow-Up Studies , Humans , Male , Obesity/complications , Osteoarthritis, Knee/complications , Overweight/complications , Overweight/diet therapy , Overweight/rehabilitation , Reference Values , Risk Assessment , Single-Blind Method , Treatment OutcomeABSTRACT
OBJECTIVES: To determine whether a hypocaloric diet higher in protein can prevent the loss of lean mass that is commonly associated with weight loss. DESIGN: An intervention study comparing a hypocaloric diet moderately high in protein to one lower in protein. SETTING: Study measurements were taken at the Wake Forest University General Clinical Research Center (GCRC) and Geriatric Research Center (GRC). PARTICIPANTS: Twenty-four post-menopausal, obese women (mean age = 58 +/- 6.6 yrs; mean BMI = 33.0 +/- 3.6 kg/m2). INTERVENTION: Two 20-week hypocaloric diets (both reduced by 2800 kcal/wk) were compared: one maintaining dietary protein intake at 30% of total energy intake (1.2-1.5 g/kg/d; HI PROT), and the other maintaining dietary protein intake at 15% of total energy (0.5-0.7 g/kg/d; LO PROT). The GCRC metabolic kitchen provided lunch and dinner meals which the women picked up 3 days per week and ate outside of the clinic. MEASUREMENTS: Body composition, including total body mass, total lean mass, total fat mass, and appendicular lean mass, assessed by dual energy x-ray absorptiometry, was measured before and after the diet interventions. RESULTS: The HI PROT group lost 8.4 +/- 4.5 kg and the LO PROT group lost 11.4 +/- 3.8 kg of body weight (p = 0.11). The mean percentage of total mass lost as lean mass was 17.3% +/- 27.8% and 37.5% +/- 14.6%, respectively (p = 0.03). CONCLUSION: Maintaining adequate protein intake may reduce lean mass losses associated with voluntary weight loss in older women.
Subject(s)
Body Composition/drug effects , Diet, Reducing , Dietary Proteins/administration & dosage , Obesity/diet therapy , Weight Loss , Absorptiometry, Photon/methods , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Aged , Body Composition/physiology , Body Mass Index , Dose-Response Relationship, Drug , Female , Humans , Middle Aged , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , PostmenopauseABSTRACT
Promoting lasting weight loss among older adults is an important public health challenge. Participation in physical activity aids in weight loss and is important for the maintenance of physical function and quality of life. However, traditional intensive lifestyle interventions place a focus on discrete bouts of structured activity, leaving much of the remainder of the day for sedentary behavior. Structured exercise and weight loss programs often produce short-term weight loss that is typically followed by weight regain, and older adults are more likely to regain weight as fat mass rather than lean mass. Preliminary evidence suggests a focus on day-long movement intended to minimize time spent sitting produces better short-term weight loss and weight maintenance. Herein we describe the design and methods for a three-arm randomized controlled trial comparing mHealth-supported weight loss (WL)â¯+â¯structured exercise (EX); WLâ¯+â¯a novel daily movement intervention (SitLess); and WLâ¯+â¯EX + SitLess. Older adults (Nâ¯=â¯180) will be randomly assigned to one of the three interventions, each comprised of a 6-month intensive phase; a 3-month transition phase; and a 9-month maintenance phase. The primary aim of the study is to determine whether the addition of SitLess to a traditional intensive lifestyle intervention comprised of dietary weight loss and structured exercise produces a larger 18-month reduction in body weight relative to WLâ¯+â¯EX and WLâ¯+â¯SitLess.
Subject(s)
Body Weight Maintenance , Exercise , Obesity/prevention & control , Weight Reduction Programs/methods , Aged , Aged, 80 and over , Humans , Obesity/therapy , Physical Functional Performance , Power, Psychological , Sedentary Behavior , TelemedicineABSTRACT
OBJECTIVE: Weight regain following intentional weight loss may negatively impact body composition, accelerating fat regain and increasing risk of physical disability. The purpose of this study was to compare long-term changes in whole body and thigh composition in obese older adults who intentionally lost and then partially regained weight to obese older adults who remained weight stable. SUBJECTS/METHODS: This pilot study analyzed total body (dual-energy X-ray absorptiometry (DXA)) and thigh (computed tomography (CT)) composition data collected from 24 older (65-79 years) adults 18 months after completion of a 5-month randomized trial that compared resistance training alone (RT) with RT plus caloric restriction (RT+CR). RESULTS: Mean loss of body mass in the RT+CR group (n=13) was 7.1±2.4 kg during the 5-month intervention (74% fat mass; 26% lean mass; all P<0.01), whereas RT (n=11) remained weight stable (+0.3±1.8 kg; P=0.64). Differential group effects were observed for all DXA and CT body composition measures at 5 months (all P⩽0.01); however, by 23 months, group differences persisted only for total body (RT+CR: 81.6±10.0 kg vs RT: 88.5±14.9 kg; P=0.03) and lean (RT+CR: 50.8±9.3 kg vs RT: 54.4±12.0 kg; P<0.01) mass. All RT+CR participants regained weight from 5 to 23 months (mean gain=+4.8±2.6 kg; P<0.01). Total fat mass and all thigh fat volumes increased, whereas thigh muscle volume decreased, during the postintervention follow-up in RT+CR (all P⩽0.01). In the RT group, body mass did not change from 5 to 23 months (-0.2±0.9 kg; P=0.87). Decreased total thigh volume, driven by the loss of thigh muscle volume, were the only postintervention body composition changes observed in the RT group (both P<0.04). CONCLUSIONS: Short-term body composition benefits of an RT+CR intervention may be lost within 18 months after completion of the intervention.
Subject(s)
Body Composition , Obesity/therapy , Overweight/therapy , Weight Loss , Absorptiometry, Photon , Aged , Body Mass Index , Caloric Restriction , Energy Intake , Female , Follow-Up Studies , Humans , Male , Muscle, Skeletal/metabolism , Pilot Projects , Resistance Training , Thigh , Time FactorsABSTRACT
Eleven clinical criteria have been proposed to limit use of lumbosacral spine roentgenograms in patients with acute low-back pain who are at risk for vertebral cancer, osteomyelitis, acute fracture, or herniated disk. We retrospectively applied the criteria to 471 patients with acute low-back pain in three teaching hospital walk-in clinics. Roentgenograms were obtained at the initial visit in 99 patients (21.1%); the number would have increased to 217 (46.1%) if the criteria had been used. The following four patient characteristics were associated with actual roentgenogram use: older age, longer duration of symptoms, reflex asymmetry, and point vertebral tenderness. Adoption of the 11 criteria studied herein may inadvertently increase roentgenogram use, thereby raising health care costs and exposing more patients to gonadal irradiation. The standard of practice in these three clinics seemed to entail use of less broad roentgenogram selection criteria. Other published guidelines for roentgenograms emphasize clinical follow-up, reserving further evaluation for patients who fail to improve after a trial of bed rest and analgesics.
Subject(s)
Back Pain/diagnostic imaging , Adolescent , Adult , Aged , Back Pain/etiology , Back Pain/therapy , Female , Humans , Lumbar Vertebrae/diagnostic imaging , Male , Middle Aged , Pregnancy , Radiography , Retrospective Studies , Sacrum/diagnostic imagingABSTRACT
Residents in primary care specialties care for many patients who smoke cigarettes, but little is known about their smoking cessation counseling (SCC). We surveyed 309 residents (72 family practice, 171 internal medicine, and 66 pediatrics residents) in 13 programs to determine their practices, knowledge, attitudes, and training in SCC. More than 90% thought physicians are responsible for SCC, the majority routinely took smoking histories, and 80% attempted to motivate patients to quit smoking. However, 25% or fewer reported discussing obstacles to quitting, setting a quit date, prescribing nicotine gum, scheduling follow-up visits, or providing self-help materials. Family practice residents used more SCC techniques (1.8) than did internal medicine (0.8) and pediatrics (0.1) residents. Only 54% of residents reported recent SCC training and 13% reported formal SCC training. Recent training correlated with the number of counseling techniques used. Residents in primary care specialties report positive attitudes but inadequate practice and training in SCC.
Subject(s)
Internship and Residency , Medicine , Patient Education as Topic , Smoking Prevention , Specialization , Attitude of Health Personnel , Education, Medical , Family Practice/education , Humans , Internal Medicine/education , Pediatrics/education , Surveys and QuestionnairesABSTRACT
Little information is available on drug effects encountered by elderly persons needing long-term treatment of their hypertension. Information on thiazides and beta-blockers suggests that these drugs have a fairly good safety profile. Individualizing drug choices and employing close laboratory and clinical follow-up should reduce the occurrence of side effects.
Subject(s)
Antihypertensive Agents/adverse effects , Hypertension/drug therapy , Age Factors , Aged , Clinical Trials as Topic , Humans , Middle AgedABSTRACT
OBJECTIVE: To determine if hypocaloric diet, diet plus low-intensity exercise, and diet plus high-intensity exercise differentially influence subcutaneous abdominal and gluteal adipocyte size in obese individuals. DESIGN: Longitudinal intervention study of hypocaloric diet, diet plus low-intensity exercise, and diet plus high-intensity exercise (calorie deficit = 2800 kcal/week, 20 weeks). SUBJECTS: Forty-five obese, middle-aged women (BMI = 33.0+/-0.6 kg/m2, age = 58+/-1 years). MEASUREMENTS: Body composition testing and adipose tissue biopsies were conducted before and after the interventions. Subcutaneous abdominal and gluteal adipocyte size was determined. RESULTS: All three interventions reduced body weight, fat mass, percent fat, and waist and hip girths to a similar degree. Diet only did not change subcutaneous abdominal adipocyte size, whereas both diet plus exercise groups significantly reduced abdominal adipocyte size. Changes in abdominal adipocyte size in the diet plus exercise groups were significantly different from that of the diet group. Gluteal adipocyte size decreased similarly in all three groups. CONCLUSION: Addition of exercise training to dietary weight loss preferentially reduces subcutaneous abdominal adipocyte size in obese women. This may be of importance for the treatment of health complications associated with subcutaneous abdominal adiposity.
Subject(s)
Adipocytes/cytology , Diet, Reducing , Exercise/physiology , Obesity/therapy , Weight Loss/physiology , Body Composition/physiology , Cell Size , Combined Modality Therapy , Female , Humans , Middle Aged , Oxygen Consumption , Subcutaneous Fat, Abdominal/cytologyABSTRACT
We describe a patient who developed pure red cell aplasia as part of a lupus-like syndrome while taking procainamide. Pure red cell aplasia resolved spontaneously after discontinuation of this drug. Although pure red cell aplasia has been reported in several patients with idiopathic systemic lupus erythematosus (SLE), this represents the first such report in a patient with drug induced SLE.
Subject(s)
Lupus Erythematosus, Systemic/complications , Procainamide/adverse effects , Red-Cell Aplasia, Pure/complications , Aged , Humans , Lupus Erythematosus, Systemic/chemically induced , Male , Red-Cell Aplasia, Pure/chemically inducedABSTRACT
Early gradual ambulation is currently recommended for patients with acute low back pain if results of neurologic examination are normal. Bed rest for up to 2 days is considered optimal. To assess management practices, we retrospectively reviewed the medical records of individuals with acute back pain treated at three independent general medicine walk-in clinics. Patients having an acute flare-up of chronic back pain were excluded. Bed rest was recommended at the initial visit for 171 patients who had normal findings on neurologic examination. The duration of recommended bed rest was recorded in 76 of these 171 patients' medical records (44%). The median duration of recommended bed rest was 5.5 days (range 1 to 14 days). Most patients (60/76 [79%]) were advised to rest in bed longer than 2 days. Even if all patients in whom duration of bed rest was not recorded had been told to rest in bed for 2 days or less, bed rest prescriptions would still have been too lengthy in 60 of these 171 patients (35%). This practice may prolong the recovery of patients with acute low back pain.
Subject(s)
Back Pain/therapy , Bed Rest , Adult , Ambulatory Care Facilities , Female , Humans , Male , North Carolina , Prognosis , Retrospective Studies , Time FactorsABSTRACT
STUDY OBJECTIVE: To evaluate the effectiveness of two teaching interventions to increase residents' performance of smoking cessation counseling. DESIGN: Randomized controlled factorial trial. SETTING: Eleven residency programs, in internal medicine (six), family medicine (three), and pediatrics (two). Programs were located in three university medical centers and four university-affiliated community hospitals. PARTICIPANTS: 261 residents who saw ambulatory care patients at least one half-day per week, and 937 returning patients aged 17 to 75 years who reported having smoked five or more cigarettes in the preceding seven days. Of the 937, 843 were eligible for follow-up, and 659 (78%) were interviewed by phone at six months. INTERVENTIONS: Two interventions (tutorial and prompt) and four groups. The tutorial was a two-hour educational program in minimal-contact smoking cessation counseling for residents. The prompt was a chart-based reminder to assist physician counseling. One group of residents received the tutorial; one, the prompt; and one, both. A fourth group received no intervention. MEASUREMENT AND RESULTS: Six months after the intervention, physician self-reports showed that residents in the tutorial + prompt and tutorial-only groups had used more counseling techniques (1.5-1.9) than had prompt-only or control residents (0.9). Residents in all three intervention groups advised more patients to quit smoking (76-79%) than did control group residents (69%). The tutorial had more effect on counseling practices than did the prompt. Physician confidence, perceived preparedness, and perceived success followed similar patterns. Exit interviews with 937 patients corroborated physician self-reports of counseling practices. Six months later, self-reported and biochemically verified patient quitting rates for residents in the three intervention groups (self-reported: 5.3-8.2%; biochemically verified: 3.4-5.7%) were higher than those for residents in the control group (self-reported: 5.2%; biochemically verified: 1.7%), though the differences were not statistically significant. CONCLUSION: A simple and feasible educational intervention can increase residents' smoking cessation counseling.