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This study investigated bone mineral and body composition changes after coronary artery bypass grafting (CABG) in men. Twenty-six men 50 to 79 years of age underwent CABG for multivessel coronary disease. Dual-energy x-ray absorptiometry was performed before surgery and 3 months and 1 year after treatment to assess bone mineral content (BMC), bone mineral density (BMD), and body composition. Through 3 months after treatment, BMD decreased at the total body, arms, and pelvis. BMC of the arm decreased and losses at the total body and legs approached significance. Fat-free mass decreased in the arms and total body but not in the legs. Neither total body nor regional fat mass changed. At the 1-year follow-up visit, 15 of the initial 26 subjects returned for dual-energy x-ray absorptiometry. Compared with before treatment, BMD decreased at the total body and legs, whereas losses at the arms approached significance. Arm BMC decreased over the 1-year post-treatment period. No changes were observed in body composition. In conclusion, CABG and the ensuing convalescence period results in considerable arm bone mineral losses through 1 year after treatment.

Background: Physical activity, physical fitness and body habitus of patients may be important predictors of outcomes after cardiac surgery. This study sought to quantify physical fitness and determine whether components of fitness enhance the prediction of outcomes in a group of patients undergoing coronary artery bypass grafting., Methods: A group of 200 patients were evaluated prior to coronary artery bypass surgery. A Veterans Specific Activity Questionnaire (VSAQ) measured aerobic capacity. A grip dynamometer assessed strength. Skin-fold thickness was used to calculate percent body fat and lean body mass index. Patients were divided into low risk (0-2.5%) and high risk (>2.5%) groups based on the STS National Cardiac Surgery Database prediction of operative mortality., Results: Patients with both a high percent body fat and a low VSAQ were at higher risk for at least one serious complication (p<0.05) and a longer postoperative length of stay (p<0.05)., Conclusion: This study suggests: 1) An index of physical fitness can be obtained preoperatively in cardiac surgical patients; 2) This information aids in the prediction of operative risk.

The objective of the study was to determine the precision of total- and regional-body composition measurements from a total-body scan using dual-energy X-ray absorptiometry (DXA). This is critical information necessary to determine the smallest change from baseline that could be detected with statistical significance when conducting longitudinal measurements of body composition variables in an individual. Twenty volunteers were scanned once each day for 4 consecutive days using a Lunar DPX-L densitometer and manufacturer-supplied software (version 1.3z). Coefficients of variation (CV, %) derived from data using the (preferred) extended research mode of analysis were 0.62, 1.89, 0.63, 2.0, 1.11, 1.10, and 1.09% for total-body bone mineral density (BMD), total percentage fat, total body tissue mass, fat mass, lean mass, bone mineral content (BMC), and total bone calcium, respectively. Regional measurements (arm, leg, trunk, pelvis, and spine) were less precise than total body measurements, with CVs in the range of 1% to 3% (but fat mass for arms was 4.26%, trunk 3.08%, BMC 3.65%). Small but statistically significant differences in mean values for most body composition variables were found when data were compared between extended and standard modes of analysis. Inconsistent use of analysis mode in a cohort or when following a patient longitudinally may negatively affect precision. We conclude that the measurement precision of total and regional body composition variables was generally comparable to the precision limits typically associated with lumbar spine and proximal femur BMD data.