Validity of Self-Reported Diagnosis of Osteoporosis in Japan Nurses' Health Study

Pregnancy and lactation-associated osteoporosis as a major type of premenopausal osteoporosis: a retrospective cohort study based on real-world data

BACKGROUND

Pregnancy and lactation-associated osteoporosis (PLO), as well as premenopausal osteoporosis, might be a predictor of future fracture. This study aimed to describe the clinical features of PLO as a subtype of premenopausal osteoporosis and to evaluate medical interventions for it.

METHODS

From an administrative claims database including 4,224,246 people in Japan, we classified women for whom the date of childbirth had been defined and who had suffered low-trauma fracture between the ages of 18-47 years as the premenopausal osteoporosis group. A fracture site for which the odds ratio for fractures occurring between 5 months before and 12 months after childbirth (around childbirth) was greater than 1 was considered the PLO site. We classified patients with a fracture at the PLO site around childbirth as the PLO group. The control group consisted of 500 women without fragility fractures. We investigated some drugs and diseases to explore fracture-causing factors, as well as medical interventions such as osteoporosis diagnosis, bone densitometry, anti-osteoporosis pharmacotherapy, and lactation inhibitors.

RESULTS

In total, 231 parous women were classified into the premenopausal osteoporosis group. The most common fracture was vertebral fracture and was likely to occur around childbirth, followed by distal radius and sacral fractures, which were rare around childbirth. Considering vertebral, pelvic, and proximal femoral fractures as PLO sites, 56 women with 57 PLO fractures were classified into the PLO group. The incidence of PLO was estimated at 460 per million deliveries. Ovulation disorder and high maternal age were associated with the development of PLO. Vertebral fracture was the most common PLO fracture. It was mainly diagnosed a few months, and possibly up to 1 year, postpartum. PLO patients with vertebral fractures underwent more medical interventions than did those with other fractures, but they were still inadequate.

CONCLUSIONS

PLO with vertebral fracture was one of the major types of premenopausal osteoporosis. The prevalence of PLO is considered to be higher than previously thought, indicating the presence of potentially overlooked patients. More timely interventions for PLO might lead to the improved management of latent patients with premenopausal osteoporosis and reduce future fracture risk.

Mandibular cortical bone structure as risk indicator in fractured and non-fractured 80-year-old men and women

Objective

To investigate the association between mandibular cortex parameters and fracture in a group of 286 men and women, 79–80 years of age.

Study design

In a cross-sectional study, the mandibular cortex was evaluated with Klemetti’s index for cortical erosion. The cortical thickness was measured with a ruler adjusting for the magnification factor. The odds ratio (OR) for fracture when having a severely eroded cortex or a cortex thickness < 3 mm was calculated.

Results

A normal cortex was found in 65% of men, whereas only 7% had a severely eroded cortex. The OR for severely eroded cortex  as fracture risk predictor was significant (2.32; 95% CI 1.3–4.2), also when the female group was evaluated separately. A significant difference was found between the mean thickness for men (3.96 mm) and women (2.92 mm), respectively. The OR for cortical thickness < 3 mm was significant (2.00; 95% CI 1.1–3.6) in the total group, but not when men and women were evaluated separately.

Conclusions

Among old women, the cortical parameters were significantly associated with prevalent fracture. In old men, other circumstances may be more important.

Association of lifestyle factors with osteoporosis and fracture in postmenopausal women: a Japanese cohort study

OBJECTIVE

Osteoporosis is a major risk factor for fracture later in life; however, few studies have examined the association of lifestyle factors with osteoporosis and fracture. This study aimed to identify factors associated with osteoporosis and fracture in postmenopausal women.

METHODS

We evaluated the association between baseline characteristics and outcomes (diagnosis of osteoporosis or incidence of fracture) in 4,427 postmenopausal women who participated in the Kyushu University Fukuoka Cohort Study on lifestyle-related diseases (baseline: February 2004 to August 2007; follow-up: February 2010 to December 2012). Among the women, 626 were diagnosed as having osteoporosis without a fracture, 294 sustained a fracture without a diagnosis of osteoporosis, and 137 were diagnosed with both osteoporosis and fracture during the average 5.3-year follow-up period; the remaining 3,370 participants were not diagnosed with osteoporosis or did not sustain a fracture. The association between lifestyle factors and the occurrence of osteoporosis and fracture was evaluated using logistic regression analysis.

RESULTS

Skipping breakfast was associated negatively with osteoporosis without fracture (odds ratio [OR] = 0.40, P = 0.009) but positively with fracture without osteoporosis (OR = 2.30, P = 0.0009). Glycated hemoglobin A1c levels were associated negatively with osteoporosis without fracture (OR = 0.81, P = 0.0003) but positively with fracture without osteoporosis (OR = 1.18, P = 0.03). Parental history of fracture and extraversion personality trait were both associated with fracture without osteoporosis.

CONCLUSIONS

Osteoporosis and fracture showed different association patterns with lifestyle factors, and no factors were correlated with an increase in both osteoporosis and fracture.