Ethnic differences in femur geometry in the women's health initiative observational study

SUMMARY

Participants in the observational study of the Women's Health Initiative (WHI) were studied to determine if ethnic differences in femur geometry can help to explain differences in hip fracture rates. Structural differences in femurs of African and Mexican-American women appear to be consistent with lower rates of hip fractures vs. whites.

INTRODUCTION

Ethnic origin has a major influence on hip fractures, but the underlying etiology is unknown. We evaluated ethnic differences in hip fracture rates among 159,579 postmenopausal participants in the WHI then compared femur bone mineral density (BMD) and geometry among a subset with dual X-ray absorptiometry (DXA) scans of the hip and total body.

METHODS

The subset included 8,206 non-Hispanic whites, 1,476 African-American (AA), 704 Mexican-American (MA), and 130 Native Americans (NA). Femur geometry derived from hip DXA using hip-structure analysis (HSA) in whites was compared to minority groups after adjustment for age, height, weight, percent lean mass, neck-shaft angle and neck length, hormone use, chronic disease (e.g., diabetes, rheumatoid arthritis, cancer), bone active medications (e.g., corticosteroids, osteoporosis therapies), and clinical center.

RESULTS

Both AA and MA women suffered hip fractures at half the rate of whites while NA appeared to be similar to whites. The structural advantage among AA appears to be due to a slightly narrower femur that requires more bone tissue to achieve similar or lower section moduli (SM) vs. whites. This also underlies their higher BMD (reduces region area) and lower buckling ratios (buckling susceptibility). Both MA and NA women had similar advantages vs. whites at the intertrochanter region where cross-sectional area and SM were higher but with no differences at the neck. NA and MA had smaller bending moments vs. whites acting in a fall on the hip (not significant in small NA sample). Buckling ratios of MA did not differ from whites at any region although NA had 4% lower values at the IT region.

CONCLUSION

Differences in the geometry at the proximal femur are consistent with the lower hip fracture rates among AA and MA women compared to whites.

Hip structural geometry and incidence of hip fracture in postmenopausal women: what does it add to conventional bone mineral density?

SUMMARY

Hip geometry measurements of outer diameter and buckling ratio at the intertrochanter and shaft of the hip dual energy X-ray absorptiometry (DXA) scan predicted incident hip fracture in postmenopausal women. These associations, independent of age, body size, clinical risk factors, and conventional areal bone mineral density, suggest hip geometry plays a role in fracture etiology and may aid in improving identification of older women at high fracture risk.

INTRODUCTION

This study examined whether hip geometry parameters predicted hip fracture independent of body size, clinical risk factors, and conventional femoral neck bone mineral density (aBMD) and whether summary factors could be identified to predict hip fracture.

METHODS

We studied 10,290 postmenopausal women from the Women's Health Initiative. Eight thousand eight hundred forty-three remained fracture free during follow-up to 11 years of follow-up, while 147 fractured their hip, and 1,300 had other clinical fractures. Hip structural analysis software measured bone cross-sectional area, outer diameter, section modulus, average cortical thickness, and buckling ratio on archived DXA scans in three hip regions: narrow neck, intertrochanter, and shaft. Hazard ratios were estimated using Cox proportional hazards models for individual parameters and for composite factors extracted from principal components analysis from all 15 parameters.

RESULTS

After adjustment for age, body size, clinical risk factors, and aBMD, intertrochanter and shaft outer diameter measurements remained independent predictors of hip fracture with hazard ratios for a one standard deviation increase of 1.61 (95% confidence interval (CI), 1.25-2.08) for the intertrochanter and 1.36 (95% CI, 1.06-1.76) for the shaft. Average buckling ratios also independently predicted incident hip fracture with hazard ratios of 1.43 (95% CI, 1.10-1.87) at the intertrochanter and 1.24 (95% CI, 1.00-1.55) at the shaft. Although two composite factors were extracted from principal components analysis, neither was superior to these individual measurements at predicting incident hip fracture.

CONCLUSIONS

Two hip geometry parameters, intertrochanter outer diameter and buckling ratio, predict incident hip fracture after accounting for clinical risk factors and aBMD.

Fracture risk increases after diagnosis of breast or other cancers in postmenopausal women: results from the Women's Health Initiative

SUMMARY

Risk for falls and fractures increases after breast cancer or other cancer diagnosis in postmenopausal women. Factors other than falls may be the major causes for the increased fracture risk.

INTRODUCTION

Cancer treatment and prognosis may have detrimental effects on bone health. However, there is a lack of prospective investigations on fracture risk among incident cancer cases.

METHODS

In this study, postmenopausal women (N = 146,959) from the Women's Health Initiative prospective cohort, who had no cancer history at baseline, were followed for up to 9 years and classified into no cancer, incident breast cancer (BC) and incident other cancer (OC) groups. The main outcomes measured were incident fractures and falls before and after cancer diagnosis. Hazards ratios (HR) and 95% confidence intervals (CI) were computed from Cox proportional hazards model.

RESULTS

While hip fracture risk before a cancer diagnosis was similar between the no cancer and cancer groups, hip fracture risk was significantly higher after BC diagnosis (HR = 1.55, CI = 1.13-2.11) and the elevated risk was even more notable after OC diagnosis (HR = 2.09, CI = 1.65-2.65). Risk of falls also increased after BC (HR = 1.15, CI = 1.06-1.25) or OC diagnosis (HR = 1.27, CI = 1.18-1.36), but could not fully explain the elevated hip fracture risk. Incident clinical vertebral and total fractures were also significantly increased after OC diagnosis (p < 0.05).

CONCLUSIONS

Postmenopausal women have significantly elevated risks for falls and fractures after a cancer diagnosis. The causes for this increased risk remained to be investigated.

Effect of oestrogen plus progestin on the incidence of diabetes in postmenopausal women: results from the Women's Health Initiative Hormone Trial

AIMS/HYPOTHESIS

Studies examining the effect of postmenopausal hormone therapy on concentrations of glucose, insulin and diabetes incidence have been inconclusive, in part because many of the studies were too small. We examined the effect of oestrogen plus progestin on diabetes incidence and insulin resistance.

METHODS

The study was a randomised, double-blind trial comparing the effect of daily 0.625 mg conjugated equine oestrogens plus 2.5 mg medroxyprogesterone acetate with that of placebo during 5.6 years of follow-up. The participants were 15,641 postmenopausal women enrolled in the Women's Health Initiative Hormone Trial. These women were aged 50 to 79 and all had an intact uterus. Diabetes incidence was ascertained by self-report of treatment with insulin or oral hypoglycaemic medication. Fasting glucose, insulin, and lipoproteins were measured in a random sample at baseline and at 1 and 3 years.

RESULTS

The cumulative incidence of treated diabetes was 3.5% in the hormone therapy group and 4.2% in the placebo group (hazard ratio 0.79, 95% CI 0.67-0.93, p=0.004). There was little change in the hazard ratio after adjustment for changes in BMI and waist circumference. During the first year of follow-up, changes in fasting glucose and insulin indicated a significant fall in insulin resistance in actively treated women compared to the control subjects (Year 1 to baseline between-group difference -0.22+/-0.10, p=0.03). INTERPRETATIONS/CONCLUSION: These data suggest that combined therapy with oestrogen and progestin reduces the incidence of diabetes, possibly mediated by a decrease in insulin resistance unrelated to body size. Future studies of alternative postmenopausal hormone therapy regimens and selective oestrogen agonists and/or antagonists should consider the effects of these regimens on insulin resistance and diabetes.

Sexual orientation and health: comparisons in the women's health initiative sample

CONTEXT

Little is known about older lesbian and bisexual women. Existing research rarely compares characteristics of these women with comparable heterosexual women.

OBJECTIVE

To compare heterosexual and nonheterosexual women 50 to 79 years on specific demographic characteristics, psychosocial risk factors, screening practices, and other health-related behaviors associated with increased risk for developing particular diseases or disease outcomes.

DESIGN

Analysis of data from 93,311 participants in the Women's Health Initiative (WHI) study of health in postmenopausal women, comparing characteristics of 5 groups: heterosexuals, bisexuals, lifetime lesbians, adult lesbians, and those who never had sex as an adult.

SETTING

Subjects were recruited at 40 WHI study centers nationwide representing a range of geographic and ethnic diversity.

PARTICIPANTS

Postmenopausal women aged 50 to 79 years who met WHI eligibility criteria, signed an informed consent to participate in the WHI clinical trial(s) or observational study, and responded to the baseline questions on sexual orientation.

MAIN OUTCOME MEASURES

Demographic characteristics, psychosocial risk factors, recency of screening tests, and other health-related behaviors as assessed on the WHI baseline questionnaire.

RESULTS

Although of higher socioeconomic status than the heterosexuals, the lesbian and bisexual women more often used alcohol and cigarettes, exhibited other risk factors for reproductive cancers and cardiovascular disease, and scored lower on measures of mental health and social support. Notable is the 35% of lesbians and 81% of bisexual women who have been pregnant. Women reporting that they never had sex as an adult had lower rates of Papanicolaou screening and hormone replacement therapy use than other groups.

CONCLUSIONS

This sample of older lesbian and bisexual women from WHI shows many of the same health behaviors, demographic, and psychosocial risk factors reported in the literature for their younger counterparts, despite their higher socioeconomic status and access to health care. The lower rates of recommended screening services and higher prevalence of obesity, smoking, alcohol use, and lower intake of fruit and vegetables among these women compared with heterosexual women indicate unmet needs that require effective interactions between care providers and nonheterosexual women.

An integrated nutrition curriculum in medical education

R25 grant support from the NIH/NCI enabled the University of Arizona to assess nutrition education, develop and evaluate specific course content, and move toward comprehensive prevention-based nutrition education in 1991-1997. Hours of nutrition education increased to 115% over baseline, and students indicated greater satisfaction with the amount of nutrition instruction they received. Especially valuable was a course in prenatal and infant nutrition that paired each student with a pregnant patient. After the grant support ended, nutrition began to be crowded out of the curriculum by other, more traditional, topics, but a 57% gain over baseline was sustained. External support for nutrition education is urgently needed.

Treatment of common anorectal disorders

Family physicians can manage most common anorectal disorders seen in office practice. Proctitis is usually caused by sexually transmitted infections that can be treated with antibiotics. Pruritus ani, anal fissures, fungal infections and hygiene problems are all amenable to simple treatments. Thrombosed external hemorrhoids can be opened and drained. Bleeding or symptomatic internal hemorrhoids can be treated with rubber-band ligation. Perirectal or ischiorectal abscesses require incision and drainage, sometimes under general anesthesia. Serious disorders such as inflammatory bowel disease and cutaneous malignancies should always be considered in the differential diagnosis of common anorectal disorders.

The cervical cap

The cervical cap is a barrier contraceptive method with an efficacy similar to that of the diaphragm. It has several advantages over other barrier contraceptives. In particular, it can be left in place for up to 48 hours, and repeated applications of spermicide are not necessary, even if sexual intercourse occurs more than once. In addition, the side effects seen with other barrier methods do not occur with the cervical cap. In some women, Papanicolaou tests may become abnormal, especially during the first three months of cap use. Therefore, careful monitoring of cervical cap users is essential.