Underweight Young Women Without Later Weight Gain Are at High Risk for Osteopenia After Midlife: The KOBE Study.
BACKGROUND
Although underweight young women are targets for interventions to prevent low bone mineral density (BMD), the relationship between change in body mass index (BMI) from youth to older age and BMD has not been widely investigated in community dwellers.


METHODS
In 749 healthy Japanese women aged 40-74 years, BMD was measured by quantitative ultrasound and anthropometric measurements, and BMI was calculated from body weight and height. The BMI of participants at age 20 years was estimated by self-reported body weight and their present height. They were classified into four groups according to the presence of underweight (BMI <18.5 kg/m2) at 20 and/or at present. Logistic regression models were used to estimate multivariate-adjusted odds ratios (ORs) of the presence of underweight at 20 and/or at present for osteopenia (BMD T score <-1 standard deviations) compared with participants with BMI ≥18.5 kg/m2both at 20 and at present.


RESULTS
The participants who were underweight both at 20 and at present had a higher OR for osteopenia compared with those with BMI ≥18.5 kg/m2at 20 and at present (OR 3.94; 95% confidence interval [CI], 1.97-7.89). Those underweight only at present also had significantly increased OR of developing osteopenia (OR 2.95; 95% CI, 1.67-5.24). The OR of those underweight only at 20 was 0.87 (95% CI, 0.51-1.48).


CONCLUSIONS
Current underweight was associated with increased risk for osteopenia among Japanese women, especially in those who were underweight both at 20 and at present. To prevent low BMD in the future, maintaining appropriate body weight might be effective for young underweight women.
Department of Preventive Medicine and Epidemiology Informatics, National Cerebral and Cardiovascular Center.
Yukako
Y
Tatsumi
Aya
A
Higashiyama
Yoshimi
Y
Kubota
Daisuke
D
Sugiyama
Yoko
Y
Nishida
Takumi
T
Hirata
Aya
A
Kadota
Kunihiro
K
Nishimura
Hironori
H
Imano
Naomi
N
Miyamatsu
Yoshihiro
Y
Miyamoto
Tomonori
T
Okamura
D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013851:Thinness / Q000453:epidemiology*; D015430:Weight Gain; D055815:Young Adult