Potential effects of fat mass and fat-free mass on energy intake in different states of energy balance.

Recently models have attempted to integrate the functional relationships of fat mass (FM) and fat-free mass (FFM) with the control of human energy intake (EI). Cross-sectional evidence suggests that at or close to EB, FFM is positively related to hunger and EI, whereas FM either shows a weak negative or no association with ad libitum EI. Further analysis suggests that the effects of FFM and FM on EI may be mediated by resting metabolic rate (RMR). These studies suggest that energy turnover is associated with EI and the largest determinant of energy requirements in most humans is FFM. During chronic positive EBs both FM and FFM expand (but disproportionately so), increasing energy demands. There is little evidence that an expanding FM exerts strong negative feedback on longer term EI. However, during chronic negative EBs FM, FFM and RMR all decrease but appetite increases. Some studies suggest that proportionate loss of FFM during weight loss predicts subsequent weight regain. Taken together these lines of evidence suggest that changes in the size and functional integrity of FFM may influence appetite and EI. Increases in FFM associated with either weight gain or high levels of exercise may 'pull' EI upwards but energy deficits that decrease FFM may exert a distinct drive on appetite. The current paper discusses how FM and FFM relationships influence appetite regulation, and how size, structure and functional integrity of FFM may drive EI in humans (i) at EB (ii) during positive EB and (iii) during negative EB.

Direct healthcare costs for 5 years post-fracture in Canada: a long-term population-based assessment.

UNLABELLED: High direct incremental healthcare costs post-fracture are seen in the first year, but total costs from a third-party healthcare payer perspective eventually fall below pre-fracture levels. We attribute this to higher mortality among fracture cases who are already the heaviest users of healthcare ("healthy survivor bias"). Economic analyses that do not account for the possibility of a long-term reduction in direct healthcare costs in the post-fracture population may systematically overestimate the total economic burden of fracture. INTRODUCTION: High healthcare costs in the first 1-2 years after an osteoporotic fracture are well recognized, but long-term costs are uncertain. We evaluated incremental costs of non-traumatic fractures up to 5 years from a third-party healthcare payer perspective. METHODS: A total of 16,198 incident fracture cases and 48,594 matched non-fracture controls were identified in the province of Manitoba, Canada (1997-2002). We calculated the difference in median direct healthcare costs for the year pre-fracture and 5 years post-fracture expressed in 2009 Canadian dollars with adjustment for expected age-related healthcare cost increases. RESULTS: Incremental median costs for a hip fracture were highest in the first year ($25,306 in women, $21,396 in men), remaining above pre-fracture baseline to 5 years in women but falling below pre-fracture costs by 5 years in men. In those who survived 5 years following a hip fracture, incremental costs remained above pre-fracture costs at 5 years ($12,670 in women, $7,933 in men). Incremental costs were consistently increased for 5 years after spine fracture in women. Total incremental healthcare costs for all incident fractures combined showed a large increase over pre-fracture costs in the first year ($137 million in women, $57 million in men), but fell below pre-fracture costs within 3-4 years. Elevated total healthcare costs were seen at year 5 in women after wrist, humerus and spine fractures, but these were somewhat offset by decreases in total healthcare costs for other fractures. CONCLUSIONS: High direct healthcare costs post-fracture are seen in the first year, but total costs eventually fall below pre-fracture levels. Among those who survive 5 years following a fracture, healthcare costs remain above pre-fracture levels.

The effect of socioeconomic status on bone density testing in a public health-care system.

INTRODUCTION AND HYPOTHESIS: An inverse relationship exists between socio-economic status (SES) and osteoporotic fractures. In publicly funded health-care systems there should be no barriers to accessing bone mineral density (BMD) testing, especially for those at increased fracture risk. Our hypothesis was that there would be a positive association between SES and BMD utilization (i.e. higher utilization rates in higher income women), resulting in disparities that disadvantage lower SES or lower income women. METHODS: A population-based BMD database from the Manitoba Bone Density Program was utilized to assess the association between SES (defined using income quintiles) and BMD utilization rates in women aged 50 years and older (n=107,944) for the 2001-2002 fiscal year. Analyses were stratified by age (50-64 years old and 65 years or older) and by a morbidity index obtained from the Johns Hopkins University Adjusted Clinical Group Case-Mix Adjustment System. RESULTS: Regression models demonstrated significantly higher BMD utilization rates among high SES women in all age and morbidity strata. Rate ratios varied from 1.76 (95% CI: 1.52-2.04) in 50- to 64-year-old women to 2.36 (95% CI: 1.60-3.49) in low morbidity women aged 65 or older. CONCLUSION: Within the context of a publicly funded health-care system significant inverse associations are demonstrated between SES and BMD utilization rates. Further research is needed to better understand the nature of these associations and how they may contribute to health outcomes.