Steven W. Lichtman

Discrepancy between Self-Reported and Actual Caloric Intake and Exercise in Obese Subjects

BACKGROUND AND METHODS Some obese subjects repeatedly fail to lose weight even though they report restricting their caloric intake to less than 1200 kcal per day. We studied two explanations for this apparent resistance to diet--low total energy expenditure and underreporting of caloric intake--in 224 consecutive obese subjects presenting for treatment. Group 1 consisted of nine women and one man with a history of diet resistance in whom we evaluated total energy expenditure and its main thermogenic components and actual energy intake for 14 days by indirect calorimetry and analysis of body composition. Group 2, subgroups of which served as controls in the various evaluations, consisted of 67 women and 13 men with no history of diet resistance. RESULTS Total energy expenditure and resting metabolic rate in the subjects with diet resistance (group 1) were within 5 percent of the predicted values for body composition, and there was no significant difference between groups 1 and 2 in the thermic effects of food and exercise. Low energy expenditure was thus excluded as a mechanism of self-reported diet resistance. In contrast, the subjects in group 1 underreported their actual food intake by an average (+/- SD) of 47 +/- 16 percent and overreported their physical activity by 51 +/- 75 percent. Although the subjects in group 1 had no distinct psychopathologic characteristics, they perceived a genetic cause for their obesity, used thyroid medication at a high frequency, and described their eating behavior as relatively normal (all P < 0.05 as compared with group 2). CONCLUSIONS The failure of some obese subjects to lose weight while eating a diet they report as low in calories is due to an energy intake substantially higher than reported and an overestimation of physical activity, not to an abnormality in thermogenesis.

Body fat by dual photon absorptiometry: Comparisons with traditional methods in Asians, blacks, and whites

Measurement of body fat by dual photon absorptiometry (FatDPA) is based on the physical principles of differential attenuation of discrete photons by fat and other soft tissue components. The three traditional methods of measuring fat are indirect, in that they depend on measuring the fat free mass (FFM) based on the assumed constancy of water, potassium, and density in the FFM. Comparison of FatDPA with fat measured by each of the indirect methods discloses systematic differences which shed light on the nature of the constancy assumptions. The purpose of this report is to study the effects of sex, age, and fatness, as well as race, on the traditional methods for estimating body fat%. In Asians (99 m, 109 f), blacks (64 m, 48 f), and whites (166 m, 212 f), 18 to 94 years, with body mass indices of 16 to 36 kg/m2, body fat measured by DPA was compared with fat by three traditional methods: total body potassium (TBK; 40K counting), total body water (TBW; HTO dilution), and underwater weighing (UWW). DPA showed the highest overall correlation with TBW and the lowest with UWW, among the three traditional methods. Asians showed the lowest correlations between FatDPA and FatUWW. On average, FatTBK was higher, while FatUWW was lower than FatDPA. The differences between FatDPA and FatOTHER by the three traditional methods were correlated with age with a negative slope in all groups, the steepest slope being for FatDPA – FatTBK in blacks. Correlations with fatness showed positive slopes for FatDPA – FatTBW and – FatUWW but not for – FatTBK. FatDPA could become a criterion method for body fat, particularly in the young, old or ill, where traditional “constants” become unreliable, if calibration can be accomplished throughout the range of subject size. Ethnicity, age, sex, and fatness as well as illness are potent variables affecting the composition of the FFM; direct measurements of fat are preferable, to avoid artifacts resulting from using indirect methods.

The current and potential capacity for cardiac rehabilitation utilization in the United States.

PURPOSE:Prior studies suggest that program capacity restraints may be an important reason for outpatient cardiac rehabilitation (CR) underutilization. We sought to measure current CR capacity and growth potential. METHODS:We surveyed all CR program directors listed in the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR) database in November 2012. Respondents reported current enrollment levels, program capacity, expansion potential, and obstacles to growth. RESULTS:Of the 812 program directors in the AACVPR database, 290 (36%) completed the full survey. Respondents represented somewhat larger programs than nonrespondents but were otherwise representative of all registered AACVPR programs. Current enrollment, estimated capacity, and estimated expansion capacity were reported at a median (interquartile range) of 140 (75, 232), 192 (100, 300), and 240 (141, 380) patients annually, respectively. Using these data, we estimated that, in the year 2012, national CR utilization was 28% (min, max: 20, 38) of eligible patients. Even with modest expansion of all existing programs operating at capacity, a maximum of 47% (min, max: 32, 67) of qualifying patients in the United States could be serviced by existing CR programs. Obstacles to increasing patient participation were primarily controllable system-related problems such as facility restraints and staffing needs. CONCLUSIONS:Even with substantial expansion of all existing CR programs, there is currently insufficient capacity to meet national service needs. This limit probably contributes to CR underutilization and has important policy implications. Solutions to this problem will likely include the creation of new CR programs, improved CR reimbursement strategies, and new models of CR delivery.

Composition of weight loss in severely obese women: A new look at old methods

Seven severely obese, outpatient dieters lost weight (mean +/- SEM, 14 +/- 1 kg), and the composition of weight lost was determined by six different models. Total body water (TBW), total body potassium (TBK), and body density, bone mineral content, and fat as determined by dual photon absorptiometry (DPA) were measured while subjects were weight-stable, before and after weight loss. Fat loss was calculated by three two-compartment models (2C-TBW, 2C-TBK, and hydrodensitometry [2C-HD]), one three-compartment model (HD with correction for water content of fat-free mass [FFM], 3C), and one four-compartment model (HD with correction for water and mineral content of FFM, 4C), and was measured directly by DPA. Mean composition of weight loss was similar for all models (mean weight lost as fat: 89% for DPA, 91.5% for 4C, 89% for 3C, 88.6% for 2C-HD, and 87% for 2C-TBW) except 2C-TBK (weight lost as fat, 66%). There was a much wider range of individual values for the 2C-TBW and 2C-TBK models (17% to 138% and 18% to 93%, respectively) than for the multicompartment models (63% to 112%) and DPA (76% to 107%). Almost opposite results were obtained for the same individual when using the 2C-TBK and 2C-TBW models. The discrepancy between these models was due to the inverse relationship between changes in TBW and TBK in the group as a whole (r = -.34, NS). In addition, TBK loss was found to be dependent on the initial level of hyperinsulinemia, calculated as the area under the 2-hour oral glucose tolerance curve.(ABSTRACT TRUNCATED AT 250 WORDS)

Dual Photon Absorptiometry: Validation of Mineral and Fat Measurements

Photons passing through human tissue undergo attenuation in relation to the specific chemical substances with which they interact. Soft tissues, consisting largely of water and organic compounds, reduce photon flux to a lesser extent than bone mineral, which contains the intermediate-Z element calcium. By selecting two appropriate photon energies and recording their attenuation, the investigator can solve simultaneous equations that subdivide body mass into two components: soft tissue and bone mineral ash (Heymsfield, et al., 1989b). Systems are now available that use either a 153-Gadolinium (153Gd) source that generates photons with energies at 100 KeV and 44 KeV or filtered X-rays with energies at about 70 KeV and 40 KeV. Instruments that rely on these sources are referred to as dual photon absorptiometers (DPA) and dual energy X-ray absorptiometers (DEXA), respectively.

Participation Rates, Process Monitoring, and Quality Improvement Among Cardiac Rehabilitation Programs in the United States: A NATIONAL SURVEY.

PURPOSE: Although strategies exist for improving cardiac rehabilitation (CR) participation rates, it is unclear how frequently these strategies are used and what efforts are being made by CR programs to improve participation rates. METHODS: We surveyed all CR program directors in the American Association of Cardiovascular and Pulmonary Rehabilitations database. Data collection included program characteristics, the use of specific referral and recruitment strategies, and self-reported program participation rates. RESULTS: Between 2007 and 2012, 49% of programs measured referral of inpatients from the hospital, 21% measured outpatient referral from office/clinic, 71% measured program enrollment, and 74% measured program completion rates. Program-reported participation rates (interquartile range) were 68% (32-90) for hospital referral, 35% (15-60) for office/clinic referral, 70% (46-80) for enrollment, and 75% (62-82) for program completion. The majority of programs utilized a hospital-based systematic referral, liaison-facilitated referral, or inpatient CR program referral (64%, 68%, and 60% of the time, respectively). Early appointments (<2 weeks) were utilized by 35%, and consistent phone call appointment reminders were utilized by 50% of programs. Quality improvement (QI) projects were performed by about half of CR programs. Measurement of participation rates was highly correlated with performing QI projects (P < .0001.) CONCLUSIONS: Although programs are aware of participation rate gaps, the monitoring of participation rates is suboptimal, QI initiatives are infrequent, and proven strategies for increasing patient participation are inconsistently utilized. These issues likely contribute to the national CR participation gap and may prove to be useful targets for national QI initiatives.

Successful Outpatient Cardiac Rehabilitation in an Adult Patient Post–surgical Repair for Tricuspid Valve Atresia and Hypoplastic Right Ventricle: A Case Study

CLINICAL CASE This case report documents outpatient cardiac rehabilitation (CR) in a 28-year-old woman born with transposition of the great vessels, tricuspid atresia, hypoplastic right ventricle, and an atrial septal defect. Surgical procedures were performed during childhood to correct these defects. In 2006, she underwent the following procedures: Fontan revision with a graft to an extracardiac total cavopulmonary connection; ASD creation; right atrial reduction; bidirectional Glenn shunt; right atrial and modified left atrial Maze procedures; and placement of an epicardial dual-chamber anti-tachycardia pacemaker. The patient was referred to CR because of postoperative complaints of fatigue, dyspnea on exertion, and low exercise tolerance. At intake, she underwent a cardiopulmonary stress test, measurement of percentage body fat, and completed the Medical Outcomes Survey 36-Item Short-Form Health Survey, Diet Intake Survey, and Center for Epidemiologic Studies Depression Scale. After completing 36 sessions, all outcomes demonstrated improvement with the exception of percentage dietary fat intake. DISCUSSION Despite increasing numbers of patients with congenital heart disease (CHD) surviving into adulthood, exercise prescription in this population remains poorly delineated. In this case, possible physiologic limitations to exercise included diminished cardiac output secondary to low pressures and flow rates in the pulmonary arteries and veins because of the absence of a functioning right ventricle, limited chronotropic response, and severe deconditioning. SUMMARY This case presents an adult patient who underwent surgical procedures to avoid heart transplantation. Despite severe CHD with many surgical procedures, and what is effectively a 2-chambered heart, she was able to successfully complete CR, graduate to home exercise, return to independent home living, and pursue her masters degree.

Reliability of abstracting performance measures: results of the cardiac rehabilitation referral and reliability (CR3) project.

BACKGROUND: Assessment of the reliability of performance measure (PM) abstraction is an important step in PM validation. Reliability has not been previously assessed for abstracting PMs for the referral of patients to cardiac rehabilitation (CR) and secondary prevention (SP) programs. To help validate these PMs, we carried out a multicenter assessment of their reliability. METHODS: Hospitals and clinical practices from around the United States were invited to participate in the Cardiac Rehabilitation Referral Reliability (CR3) Project. Twenty-nine hospitals and 23 outpatient centers expressed interest in participating. Seven hospitals and 6 outpatient centers met participation criteria and submitted completed data. Site coordinators identified 35 patients whose charts were reviewed by 2 site abstractors twice, 1 week apart. Percent agreement and the Cohen &kgr; statistic were used to describe intra- and interabstractor reliability for patient eligibility for CR/SP, patient exceptions for CR/SP referral, and documented referral to CR/SP. RESULTS: Results were obtained from within-site data, as well as from pooled data of all inpatient and all outpatient sites. We found that intra-abstractor reliability reflected excellent repeatability (≥90% agreement; &kgr; ≥ 0.75) for ratings of CR/SP eligibility, exceptions, and referral, both from pooled and site-specific analyses of inpatient and outpatient data. Similarly, the interabstractor agreement from pooled analysis ranged from good to excellent for the 3 items, although with slightly lower measures of reliability. CONCLUSIONS: Abstraction of PMs for CR/SP referral has high reliability, supporting the use of these PMs in quality improvement initiatives aimed at increasing CR/SP delivery to patients with cardiovascular disease.

Poster 20: Effects of a cognitive training program on outcomes in extended acute inpatient medical rehabilitation for patients with cardiac disease1

Abstract Objectives: To test the hypotheses that (1) a structured learning environment and computer-based cognitive training will improve cognition in elderly, extended acute (phase 1B) medical inpatients admitted for deconditioning secondary to cardiac disease, who demonstrate cognitive deficits on admission; and (2) a change in cognition will lead to improved functional outcomes. Design: Experimental, prospective, randomized, single-factor, pretest-posttest design. Setting: Phase 1B inpatient medical rehabilitation unit using a multidisciplinary approach. Participants: 50 patients (47 completed the study) admitted to a phase 1B inpatient medical rehabilitation unit who met study inclusion criteria (Mini-Mental State Examination score, 1wk length of stay [LOS], cardiac diagnosis) were randomly assigned to a cognitive training group (experimental, n=25) or standard treatment (control, n=22) group. Interventions: Groups received 3 to 6 hours of daily standard therapy. The experimental group also received computer-based cognitive training sessions 3 times/wk, 20 min/session, and a morning and evening group session designed to improve memory and organization skills. Main Outcome Measures: For hypothesis 1, cognitive portion of the FIM™ instrument. For hypothesis 2, LOS, falls, number of home services on discharge, discharge placement, total and motor FIM scores, and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Results: There were no significant differences in baseline characteristics. The experimental group showed a significantly greater percentage improvement for the cognitive portion of the FIM (23.6%±18.4% vs 11.8%±17.2%, P =.035). LOS, falls, home services, discharge placement, total FIM, motor FIM, and 7 of 8 of the SF-36 subscales did not differ between the groups. The control group showed a significantly greater percentage improvement on the physical functioning subscale of the SF-36 (130.0%±67.1% vs 83.3%±66.5%, P =.008). Conclusions: The structured learning environment and computer-based training program showed improvements in cognition, as measured by the cognitive portion of the FIM. However, there were no differences in functional outcomes.

Total body bone density in amenorrheic runners

Many studies have suggested that the positive effect of running on bone mass does not fully compensate for the negative effects of athletic amenorrhea. These studies have made this conclusion based on measurements of bone at a limited number of sites. This study used dual-photon absorptiometry to measure bone mineral content and bone mineral density in the total body as well as in several regions in amenorrheic runners (N = 13), eumenorrheic runners (N = 13), and sedentary controls (N = 12). The subjects were 21–35 years old. Runners had run at least 40 km/week for at least the past 3 years. Controls had body mass indices similar to those of the runners. The amenorrheic women had significantly lower values for total bone mineral content (P = .01), total bone mineral density (P = .04), and total bone mineral content as a percent of normal values (P = .04) than eumenorrheic women, but they were not significantly different from the controls. When total bone mineral content and total bone mineral density were adjusted for body weight, there were no significant differences among the groups. The eumenorrheic subjects had significantly greater bone mineral density in the trunk than the amenorrheic women; eumenorrheics and controls had significantly greater bone mineral density in the spine compared with amenorrheics. Lumbar spine bone mineral density showed a trend toward greatest values for controls and lowest for amenorrheic women (P = .069), although this measurement is relatively imprecise. Arms and legs showed no significant differences among the groups. Despite their physical activity, amenorrheic runners have a lower total body bone mineral density than their eumenorrheic counterparts and lower bone mineral density in the trunk and spine regions of the body. However, the lower values seem proportional to their lower body weight.