Impact of increased overweight on the projected prevalence of osteoporosis in older women.
BACKGROUND
Overweight is increasing worldwide, but particularly in the United States of America. Higher body weight is associated with higher bone density, so our goal was to estimate whether the higher prevalence of overweight is likely to reduce osteoporosis among older women.


METHODS
We calculated the prevalence of osteoporosis by weight status in older women using data from the third National Health and Nutrition Examination Survey (NHANES III, 1988-94). We defined overweight as a body mass index (BMI) >or=25 and osteoporosis as a femur neck bone mineral density (BMD) value 2.5 standard deviations or more below the mean of that of young women. To estimate the expected prevalence of osteoporosis, we applied the prevalence of osteoporosis by weight status from NHANES III to the corresponding weight status prevalence from NHANES 1999-2002.


RESULTS
Of older women in NHANES 1999-2002, 68% were overweight compared to 62% in NHANES III. Overweight status was significantly related to osteoporosis prevalence (P < 0.001). However, the expected prevalence of osteoporosis in NHANES 1999-2002 was only slightly lower than that seen in NHANES III (16.8% vs 18.1%, respectively).


CONCLUSIONS
The increasing prevalence of overweight among older US women appears unlikely to be accompanied by a significant reduction in osteoporosis.
Looker
A C
AC
National Center for Health Statistics, Centers for Disease Control and Prevention, Room 4201, 3311 Toledo Rd, Hyattsville, MD 20782, USA. acl1@cdc.gov
Flegal
K M
KM
Melton
L J
LJ
D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015519:Bone Density; D005260:Female; D005272:Femur Neck / Q000503:physiopathology; D006306:Health Surveys; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000453:epidemiology / Q000503:physiopathology*; D050177:Overweight / Q000502:physiology*; D015995:Prevalence; D014481:United States / Q000453:epidemiology