Bone mineral density of 289 healthy middle aged and old people in Dongcheng district, Beijing

Ping ZENG; Yi ZHANG; Ninghua LI

ABSTRACT

BACKGROUND:

Some researches demonstrate that bone mineral density of healthy males and females whose ages range from 20 to 40 years reaches the peak.With the age growing,bone mineral density decreases gradually so as to cause osteoporosis.

OBJECTIVE:

To analyze changes of bone mineral density and characteristics of osteoporosis in 289 healthy middle and old aged people in two communities,Dongcheng district,Beijing.

DESIGN:

Cross-sectional study.

SETTING:

Beijing Institute of Geriatrics,Beijing Hospital,Ministry of Health.

PARTICIPANTS:

A total of 289 healthy residents over 45 years old were randomly selected from two communities,Dongcheng district,Beijing from June to September 1998.There were 136 males and 153 females,and their ages ranged from 45 to 85 years.Exclusion criteria① Hepatic and renal disfunction;② effects of various factors on bone metabolism (various acute and chronic diseases;histories of long-term administration of hormone and calcium preparation;19 kg/m2＞index of body mass＞28 kg/m2;long-term bed over three months;unusual occupation).All subjects provided the confirmed consent.

METHODS:

Dual-energy X-ray bone density meter (Lunar Company,USA) was used to measure bone mineral density of all subjects at proximal end of left femur (neck of femur,great troch,Ward's triangle) and antero-posterior position of lumbar spine (L2-4).Diagnostic criteria of osteoporosis set by WHO and peak bone value acquired from a tackle key program were used to determine diagnostic standards of osteoporosis at various sites.The diagnostic standards were detailed as followsneck of femur0.665 g/cm2 of males and 0.677 g/cm2 of females;great troch0.598 g/cm2 of males and 0.506 g/cm2 of females;Ward's triangle0.492 g/cm2 of males and 0.514 g/cm2 of females;L2-40.760 g/cm2 of males and 0.835 g/cm2 of females.Meanwhile,peak bone value acquired by Key Program During the Ninth Five-Year Plan Period was used to calculate bone mineral density losing rate and prevalent rate of osteoporosis.MAIN OUTCOME

MEASURES:

Bone mineral density,bone mineral density losing rate and prevalent rate of osteoporosis at various sites in patients with the two sexes.

RESULTS:

All 289 subjects were involved in the final analysis.① With the age growing,bone mineral density in the males was not increased obviously;however,decrease of bone mineral density and bone mineral density loss in the females were remarkable,especially over 55 years old.② Analysis of bone mineral density losing rate based on various sitesbone mineral density losing rate in both males and females ranged Ward's triangle＞neck of femur＞great troch＞L2-4.③ Prevalent rate of osteoporosis was increased gradually with the age growing;especially,that in the females was obviously higher than that in the males,and there was significant difference (P＜ 0.01).Osteoporosis highly occurred in femur,and then in Ward's triangle and L2-4.

CONCLUSION:

With the age growing of the females,osteoporosis easily onsets in neck of femur,Ward's triangle and L2-4;especially menopause is the main risk factor for osteoporosis.