Effect of weight loss and exercise therapy on bone metabolism and mass in obese older adults: a one-year randomized controlled trial.
BACKGROUND
Although weight loss and exercise ameliorates frailty and improves cardiac risk factors in obese older adults, the long-term effect of lifestyle intervention on bone metabolism and mass is unknown.


OBJECTIVE
The objective was to evaluate the effects of diet-induced weight loss in conjunction with exercise on bone metabolism and mass in obese older adults.


METHODS
We conducted a one-year randomized, controlled clinical trial in a university-based research center.


METHODS
Twenty-seven frail, obese (body mass index = 39 +/- 5 kg/m(2)), older (age 70 +/- 5 yr) adults participated in the study.


METHODS
Participants were randomly assigned to diet and exercise (treatment group; n = 17) or no therapy (control group; n = 10).


METHODS
Body weight decreased in the treatment group but not in the control group (-10 +/- 2 vs. +1 +/- 1%, P < 0.001). Compared with the control group, the treatment group had greater changes in bone mass, bone markers, and hormones, including 1) bone mineral density (BMD) in total hip (0.1 +/- 2.1 vs. -2.4 +/- 2.5%), trochanter (0.2 +/- 3.3 vs. -3.3 +/- 3.1%), and intertrochanter (0.3 +/- 2.7 vs. -2.7 +/- .3.0%); 2) C-terminal telopeptide (12 +/- 35 vs. 101 +/- 79%) and osteocalcin (-5 +/- 15 vs. 66 +/- 61%); and 3) leptin (2 +/- 12 vs. -30 +/- 25%) and estradiol (0.1 +/- 14% vs. -14 +/- 21%) (all P < 0.05). Changes in weight (r = 0.55), bone markers (r = -0.54), and leptin (r = 0.61) correlated with changes in hip BMD (all P < 0.05).


CONCLUSIONS
Weight loss, even when combined with exercise, decreases hip BMD in obese older adults. It is not known whether the beneficial effects of weight loss and exercise on physical function lower the overall risk of falls and fractures, despite the decline in hip BMD.
Villareal
Dennis T
DT
Division of Geriatrics and Nutritional Science, Center for Human Nutrition, Washington University School of Medicine, 4488 Forest Park Boulevard, St. Louis, MO 63108, USA. dvillare@im.wustl.edu
Shah
Krupa
K
Banks
Marian R
MR
Sinacore
David R
DR
Klein
Samuel
S
D000368:Aged; D001835:Body Weight / Q000502:physiology; D015519:Bone Density; D001862:Bone Resorption / Q000517:prevention & control; D001842:Bone and Bones / Q000378:metabolism* / Q000473:pathology*; D003131:Combined Modality Therapy; D004038:Diet, Reducing; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D009765:Obesity / Q000473:pathology / Q000628:therapy*; D009929:Organ Size / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology*