Depot medroxyprogesterone acetate use and periodontal health in 15- to 44-year-old US females

BACKGROUND

It has been suggested that progestins may have an inflammatory component and/or increase in prostaglandin synthesis. Thus, extended progestin use may be associated with higher risk of periodontal diseases. This study investigates the association between depot medroxyprogesterone acetate (DMPA) injectable contraception and the prevalence of periodontal diseases among US premenopausal females.

METHODS

Data for this cross-sectional analysis comes from the 1999 to 2004 National Health and Nutrition Examination Surveys. This analysis includes 4,460 US females (15 to 44 years of age) with complete DMPA usage and periodontal status data.

RESULTS

Current and past DMPA use was 4.1% and 12.0%, respectively. The prevalence of gingivitis was 53.9% for females who reported having used DMPA compared with 46.1% for DMPA never-users. Females taking DMPA were more likely to be young, single, and non-white, have a history of smoking, have lower levels of education and income, and have ≥1 live births and were less likely to visit the dentist. Using logistic regression, DMPA use was associated with an increased risk of gingivitis (odds ratio [OR] =1.7; 95% confidence interval [CI] = 1.09 to 1.67) and periodontitis (DMPA, OR = 1.49; 95% CI = 1.01 to 2.22) after adjusting for age, race, education, poverty income ratio, dental care use, and smoking status. A significant interaction between smoking status and DMPA use was also found (P = 0.029).

CONCLUSIONS

This study suggests that DMPA use may be associated with periodontal diseases. Additional investigation is warranted as a result of the disproportionate usage of DMPA among low-income populations who are at an increased risk for poor dental health.

Relationships between menopausal and mood symptoms and EEG sleep measures in a multi-ethnic sample of middle-aged women: the SWAN sleep study

STUDY OBJECTIVES

Examine associations of vasomotor and mood symptoms with visually scored and computer-generated measures of EEG sleep.

DESIGN

Cross-sectional analysis.

SETTING

Community-based in-home polysomnography (PSG).

PARTICIPANTS

343 African American, Caucasian, and Chinese women; ages 48-58 years; pre-, peri- or post-menopausal; participating in the Study of Women's Health Across the Nation Sleep Study (SWAN Sleep Study).

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Measures included PSG-assessed sleep duration, continuity, and architecture, delta sleep ratio (DSR) computed from automated counts of delta wave activity, daily diary-assessed vasomotor symptoms (VMS), questionnaires to collect mood (depression, anxiety) symptoms, medication, and lifestyle information, and menopausal status using bleeding criteria. Sleep outcomes were modeled using linear regression. Nocturnal VMS were associated with longer sleep time. Higher anxiety symptom scores were associated with longer sleep latency and lower sleep efficiency, but only in women reporting nocturnal VMS. Contrary to expectations, VMS and mood symptoms were unrelated to either DSR or REM latency.

CONCLUSIONS

Vasomotor symptoms moderated associations of anxiety with EEG sleep measures of sleep latency and sleep efficiency and was associated with longer sleep duration in this multi-ethnic sample of midlife women.

Longitudinal change in reproductive hormones and depressive symptoms across the menopausal transition: results from the Study of Women's Health Across the Nation (SWAN)

CONTEXT

The contribution of reproductive hormones to mood has been the focus of considerable research. Results from clinical and epidemiological studies have been inconsistent. It remains unclear whether alterations in serum hormone levels across the menopausal transition are linked to depressive symptoms.

OBJECTIVES

To evaluate the relationship between serum hormone levels and high depressive symptoms and whether hormone levels or their change might explain the association of menopausal status with depressive symptoms previously reported in a national sample of midlife women.

DESIGN

A longitudinal, community-based, multisite study of menopause. Data were collected at baseline and annually from December 1995 to January 2008 on a range of factors. Early follicular phase serum samples were assayed for levels of estradiol, follicle-stimulating hormone, testosterone, and dehydroepiandrosterone sulfate.

SETTING

Seven communities nationwide.

PARTICIPANTS

A community-based sample of 3302 multiethnic women, aged 42 to 52 years, still menstruating and not using exogenous reproductive hormones. Main Outcome Measure Depressive symptoms assessed with the Center for Epidemiological Studies Depression Scale (CES-D). The primary outcome was a CES-D score of 16 or higher.

RESULTS

In multivariable random-effects logistic regression models, log-transformed testosterone level was significantly positively associated with higher odds of a CES-D score of 16 or higher (odds ratio = 1.15; 95% confidence interval, 1.01-1.31) across 8 years, and a larger increase in log-transformed testosterone from baseline to each annual visit was significantly associated with increased odds of a CES-D score of 16 or higher (odds ratio = 1.23; 95% confidence interval, 1.04-1.45). Less education, being Hispanic, and vasomotor symptoms, stressful life events, and low social support at each visit were each independently associated with a CES-D score of 16 or higher. No other hormones were associated with a CES-D score of 16 or higher. Being perimenopausal or postmenopausal compared with being premenopausal remained significantly associated with a CES-D score of 16 or higher in all analyses.

CONCLUSIONS

Higher testosterone levels may contribute to higher depressive symptoms during the menopausal transition. This association is independent of menopausal status, which remains an independent predictor of higher depressive symptoms.

Lack of quadriceps dysfunction in women with early knee osteoarthritis

Quadriceps dysfunction, specifically weakness and central activation failure (CAF), has been implicated in the development and progression of knee osteoarthritis (OA), though few data are available to confirm its presence in early OA. The purpose of this study was to determine the presence and magnitude of quadriceps dysfunction in those with and without early knee OA. Thirty-five female volunteers were classified into two groups, OA (n=22) and control (n=13), based on the presence [Kellgren-Lawrence (K-L) grade 2] or absence (K-L grade 0-1) of mild OA, respectively. Isometric quadriceps strength and central activation ratio (CAR) were assessed and compared between groups utilizing a one-way ANOVA. Frequency statistics and Fisher's exact test were used to compare the percentage of women with and without CAF between groups. Quadriceps strength (control: 1.47+/-0.62 Nm/kg; OA: 1.30+/-0.62 Nm/kg; p=0.45) was not significantly different for women with and without mild OA. Further, the CAR (control: 0.91+/-0.07; OA: 0.87+/-0.12; p=0.19) did not differ between groups; however, women in both groups presented with CAF (control: 54%; OA: 73%; p=0.29). Our results suggest that the women with mild osteoarthritis do not present with quadriceps dysfunction.

Knee osteoarthritis in obese women with cardiometabolic clustering

OBJECTIVE

To assess the role of obesity and metabolic dysfunctionality with knee osteoarthritis (OA), knee joint pain, and physical functioning performance, adjusted for joint space width (JSW) asymmetry.

METHODS

Knee OA was defined as a Kellgren/Lawrence score > or =2 on weight-bearing radiographs. Obesity was defined as a body mass index > or =30 kg/m2. Cardiometabolic clustering classification was based on having > or =2 of the following factors: low levels of high-density lipoprotein cholesterol; elevated levels of low-density lipoprotein cholesterol, triglycerides, blood pressure, C-reactive protein, waist:hip ratio, or glucose; or diabetes mellitus. The difference between lateral and medial knee JSW was used to determine joint space asymmetry.

RESULTS

In a sample of women (n = 482, mean age 47 years), prevalences of knee OA and persistent knee pain were 11% and 30%, respectively. The knee OA prevalence in nonobese women without cardiometabolic clustering was 4.7%, compared with 12.8% in obese women without cardiometabolic clustering and 23.2% in obese women with cardiometabolic clustering. Nonobese women without cardiometabolic clustering were less likely to perceive themselves as limited compared with women in all other obesity/cardiometabolic groups (P < 0.05). Similar associations were seen with knee pain and physical functioning measures. The inclusion of a joint space asymmetry measure was associated with knee OA but not with knee pain or physical functioning.

CONCLUSION

Knee OA was twice as frequent in obese women with cardiometabolic clustering compared with those without, even when considering age and joint asymmetry. Obesity/cardiometabolic clustering was also associated with persistent knee pain and impaired physical functioning.

Cognitive functioning is related to physical functioning in a longitudinal study of women at midlife

BACKGROUND

Studies have reported declines with age in cognitive or physical functioning, but rarely identify whether these are parallel or linked events in the same study. Furthermore, most research in this area has focused on persons in late life rather than midlife.

OBJECTIVE

The objective of the study was to determine (1) if cognitive functioning was related to physical functioning and whether this relationship persisted after adjustment for age, menopause status, metabolic status, depression and socioeconomic resources, and (2) if changes in physical functioning were associated with changes in cognitive functioning over a 4-year follow-up period.

METHODS

Data were from the Study of Women's Health Across the Nation (SWAN), a multi-site, longitudinal study of women aged 46-56 years at follow-up examination 4. Three follow-up examinations (study years 04, 06 and 08) included measures of physical functioning perception (MOS SF-36) and cognitive functioning [Symbol Digit Modality Test (SDMT), Digit Span Backward Test (DSBT), and East Boston Memory Test (EBMT)] (n = 2,405).

RESULTS

Women with lower cognitive functioning scores also had lower perceived physical functioning scores. While adjustment for covariates attenuated the association between perceived physical functioning and both the SDMT and EBMT cognitive measures, these associations remained statistically significant. Additionally, the 4-year change in perceived physical functioning was significantly associated with the 4-year change in the EBMT.

CONCLUSIONS

At midlife, there were associated declines in cognitive and perceived physical functioning scores, commencing at midlife in women.

Lipid changes during the menopause transition in relation to age and weight: the Study of Women's Health Across the Nation

Few studies have prospectively examined lipid changes across the menopause transition or in relation to menopausal changes in endogenous hormones. The relative independent contributions of menopause and age to lipid changes are unclear. Lipid changes were examined in relation to changes in menopausal status and in levels of estradiol and follicle-stimulating hormone in 2,659 women followed in the Study of Women's Health Across the Nation (1995-2004). Baseline age was 42-52 years, and all were initially pre- or perimenopausal. Women were followed annually for up to 7 years (average, 3.9 years). Lipid changes occurred primarily during the later phases of menopause, with menopause-related changes similar in magnitude to changes attributable to aging. Total cholesterol, low density lipoprotein cholesterol, triglycerides, and lipoprotein(a) peaked during late peri- and early postmenopause, while changes in the early stages of menopause were minimal. The relative odds of low density lipoprotein cholesterol (> or =130 mg/dL) for early postmenopausal, compared with premenopausal, women were 2.1 (95% confidence interval: 1.5, 2.9). High density lipoprotein cholesterol also peaked in late peri- and early postmenopause. Results for estradiol and follicle-stimulating hormone confirmed the results based on status defined by bleeding patterns. Increases in lipids were smallest in women who were heaviest at baseline.

The effect of oral contraceptives on bone mass and stress fractures in female runners

PURPOSE

To determine the effect of oral contraceptives (OC) on bone mass and stress fracture incidence in young female distance runners.

METHODS

One hundred fifty competitive female runners ages 18-26 yr were randomly assigned to OC (30 microg of ethinyl estradiol and 0.3 mg of norgestrel) or control (no intervention) for 2 yr. Bone mineral density (BMD) and content (BMC) were measured yearly by dual x-ray absorptiometry. Stress fractures were confirmed by x-ray, magnetic resonance imaging, or bone scan.

RESULTS

Randomization to OC was unrelated to changes in BMD or BMC in oligo/amenorrheic (N=50) or eumenorrheic runners (N=100). However, treatment-received analyses (which considered actual OC use) showed that oligo/amenorrheic runners who used OC gained about 1% per year in spine BMD (P<0.005) and whole-body BMC (P<0.005), amounts similar to those for runners who regained periods spontaneously and significantly greater than those for runners who remained oligo/amenorrheic (P<0.05). Dietary calcium intake and weight gain independently predicted bone mass gains in oligo/amenorrheic runners. Randomization to OC was not significantly related to stress fracture incidence, but the direction of the effect was protective in both menstrual groups (hazard ratio [95% CI]: 0.57 [0.18, 1.83]), and the effect became stronger in treatment-received analyses. The trial's statistical power was reduced by higher-than-anticipated noncompliance.

CONCLUSION

OC may reduce the risk for stress fractures in female runners, but our data are inconclusive. Oligo/amenorrheic athletes with low bone mass should be advised to increase dietary calcium and take steps to resume normal menses, including weight gain; they may benefit from OC, but the evidence is inconclusive.

Risk factors for stress fracture among young female cross-country runners

PURPOSE

To identify risk factors for stress fracture among young female distance runners.

METHODS

Participants were 127 competitive female distance runners, aged 18-26, who provided at least some follow-up data in a randomized trial among 150 runners of the effects of oral contraceptives on bone health. After completing a baseline questionnaire and undergoing bone densitometry, they were followed an average of 1.85 yr.

RESULTS

Eighteen participants had at least one stress fracture during follow-up. Baseline characteristics associated (P<0.10) in multivariate analysis with stress fracture occurrence were one or more previous stress fractures (rate ratio [RR] [95% confidence interval]=6.42 (1.80-22.87), lower whole-body bone mineral content (RR=2.70 [1.26-5.88] per 1-SD [293.2 g] decrease), younger chronologic age (RR=1.42 [1.05-1.92] per 1-yr decrease), lower dietary calcium intake (RR=1.11 [0.98-1.25] per 100-mg decrease), and younger age at menarche (RR=1.92 [1.15-3.23] per 1-yr decrease). Although not statistically significant, a history of irregular menstrual periods was also associated with increased risk (RR=3.41 [0.69-16.91]). Training-related factors did not affect risk.

CONCLUSION

The results of this and other studies indicate that risk factors for stress fracture among young female runners include previous stress fractures, lower bone mass, and, although not statistically significant in this study, menstrual irregularity. More study is needed of the associations between stress fracture and age, calcium intake, and age at menarche. Given the importance of stress fractures to runners, identifying preventive measures is of high priority.

Characterizing daily urinary hormone profiles for women at midlife using functional data analysis

The availability of daily hormone values for entire menstrual cycles offers an opportunity to apply new analytic techniques that confirm current knowledge and provide new insights into patterns of changing hormone profiles in women as they transition to the menopause. The Study of Women's Health Across the Nation (SWAN) collected urine samples during 1997-1999 from one menstrual cycle or up to 50 days from 848 women who live in seven cities across the United States. These samples were assayed for the urinary forms of estrogen, progesterone, follicle-stimulating hormone, and luteinizing hormone. The authors used functional data analysis to study variability in the hormone patterns of 572 of the 848 pre- and early-perimenopausal women with evidence of a luteal transition. Functional data analysis enabled the authors to identify asymmetries in women's hormone patterns related to cycle length that are not captured with single hormone value comparisons. Longer cycles were characterized by increasing dyssynchrony between follicle-stimulating hormone and luteinizing hormone in the luteal phase.

Bone mineral density loss and recovery during 48 months in first-time users of depot medroxyprogesterone acetate

OBJECTIVE

To compare changes in bone mineral density (BMD) during 48 months between first-time depot medroxyprogesterone acetate (MPA) users, during use and after discontinuation, to controls.

DESIGN

Longitudinal study.

SETTING

Academic community.

PATIENT(S)

Women 18-35 years, newly initiating depot MPA (n = 178) and controls (n = 145) not using hormonal contraception.

MAIN OUTCOME MEASURE(S)

The BMD of the hip and spine, measured at 3-month intervals, by dual energy roentgen absorptiometry.

RESULTS

Hip and spine BMD declined during 48 months of depot MPA use by 7.7% +/- 0.11% (mean +/- SE) and 6.4% +/- 0.36%, respectively. The BMD of controls declined <or=1.6% +/- 0.30%. Hip and spine BMD loss slowed to <0.6% after 48 months of depot MPA use. After discontinuation, BMD increased from 0.3% to 2.0% per year depending on length of depot MPA use and bone site. The longest depot MPA users remained 4.7% and 2.9% lower than hip and spine baseline values, respectively, 18 months after discontinuation.

CONCLUSION(S)

Depot MPA-related BMD loss is substantial but occurs mostly during the first 2 years of DMPA use. Therefore, longer use may not substantially increase the risk of osteoporosis. The prolonged recovery time suggests the need to consider timing of use in relation to menopause or other factors that may impede bone remodeling.

Relation of cardiovascular risk factors in women approaching menopause to menstrual cycle characteristics and reproductive hormones in the follicular and luteal phases

CONTEXT

Menstrual cycle characteristics may be associated with cardiovascular disease (CVD) risk.

OBJECTIVE

The objective of this study was to describe the relationships between menstrual cycle characteristics and daily reproductive hormone measures with CVD risk factors in middle-aged women.

DESIGN AND SETTING

Cross-sectional associations were examined between CVD risk factors and urinary LH, FSH, estrone conjugates, and pregnanediol glucuronide (Pdg) measured across one menstrual cycle or 50 d.

PARTICIPANTS

Menstruating women (n = 500) who were free from diabetes or past stroke or heart attack enrolled in the Daily Hormone Study-Study of Women's Health across the Nation were studied.

MAIN OUTCOME MEASURES

Body mass index (BMI), blood pressure, hemostatic, and metabolic factors were measured.

RESULTS

Few differences existed in risk factors between women with evidence of luteal activity and those with no evidence of luteal activity. Associations between elevated CVD risk factors and long cycle length were reduced substantially by age and BMI adjustments. Those with lower estrone conjugate and PdG averaged across the follicular phase had higher waist circumference, triglycerides, insulin, plasminogen activator inhibitor type-1, tissue type plasminogen activator-antigen, and factor VIIc levels in age- and BMI-adjusted analyses (P < 0.05).

CONCLUSIONS

In midlife menstruating women, a longer cycle length was related to CVD risk factors, in large part through their common association with BMI. More favorable levels of metabolic and hemostatic factors were associated with higher levels of follicular-phase estrogen, a pattern consistent with a more competent ovary, and higher levels of follicular-phase PdG, perhaps of adrenal origin. Metabolic and hemostatic factors may be sensitive to hormonal variation during the early perimenopausal transition.

Weight, fat mass, and central distribution of fat increase when women use depot-medroxyprogesterone acetate for contraception

OBJECTIVE

To compare longitudinal changes in weight, body fat, and ratio of central to peripheral fat mass among first-time depot-medroxyprogesterone acetate (DMPA) users to women using no hormonal contraception, and to evaluate user characteristics associated with that change.

DESIGN

Prospective longitudinal study.

SUBJECTS

Healthy women, aged 18-35 y, using DMPA for contraception (n=178) and women using no hormonal contraception (n=145).

MEASUREMENTS

Weight, body fat, and the central distribution of fat, measured at 3-month intervals for 30 months, by electronic scale and dual-energy X-ray absorptiometry (DEXA). The ratio of central to peripheral distribution of body fat was computed by dividing the body fat in the conventional DEXA trunk region of interest (ROI) by the ROI's that encompass the arms, hips and legs.

RESULTS

Women using DMPA had a significantly greater increase in all measures of fatness than women using no hormonal method of contraception (P<0.03). The observed weight of DMPA users increased from a mean of 69.4 kg (s.d.=16.9) at baseline to 75.5 kg (s.d.=25.0) at 30 months; an increase of 6.1 kg (8.8.%). Fat mass increased from a mean of 25.3 kg (s.d.=12.6 kg) at baseline to 31.4 kg (s.d.=17.8); an increase of 6.1 kg (23.6%) in DMPA users. The ratio of central to peripheral fat mass in DMPA users changed from 0.95 (s.d.=0.155) at baseline to 1.01(s.d.=0.198) at 30 months. In contrast, weight, fat mass and the ratio of central to peripheral fat mass of control participants remained virtually unchanged over the same time period. Women with higher baseline physical activity levels had a smaller increase in body fat (P=0.003) and the fat ratio (P=0.03), but not weight (P=0.48). No other user characteristics including, smoking, past oral contraceptive use or previous pregnancies predicted change in level of fatness.

CONCLUSIONS

This study has demonstrated a change in body composition toward greater fatness and toward a central redistribution of fat among DMPA users as compared to controls and provides important information to be used when counseling women regarding contraceptive methods. Given the potential long-term implication of these changes, further study is recommended to determine whether the gains in fatness are reversed following DMPA discontinuation and to examine the role of progestins in the development and maintenance of obesity.

Age at natural menopause and factors associated with menopause state among Puerto Rican women aged 40-59 years, living in Puerto Rico

OBJECTIVE

The timing of menopause is associated with multiple health outcomes in female populations including all-cause mortality, heart disease, breast cancer, and osteoporosis. Although research suggests that age at menopause varies in different ethnic groups, data on age at menopause among Hispanic women are limited.

DESIGN

The present cross-sectional study estimates age at natural menopause among a sample of 1,272 Puerto Rican women aged 40 to 59 years who participated in health fairs held in 22 municipalities of Puerto Rico between May 2000 and November 2001. Cox proportional hazard regression analysis was used to characterize age at natural menopause and its association with relevant covariates.

RESULTS

The overall adjusted median age at natural menopause was 51.3 years. Current employment (hazard ratio = 0.75, 95% CI: 0.59-0.95) and parity of two or three children as compared with having no children or one child (hazard ratio = 0.73, 95% CI: 0.54-0.98) were associated with a later menopause.

CONCLUSIONS

This study provides a robust estimate of age at menopause for Puerto Rican women, which is similar to overall estimates previously reported for US populations, but higher than estimates for other Hispanic populations. Our results confirm attributes associated with age at menopause and provide information relevant to understanding the potential chronic disease burden of Puerto Rican women as they age.

A longitudinal study of the predictors of prevalence and severity of symptoms commonly associated with menopause

OBJECTIVE

To delineate the role of hormone levels, menopause status, exogenous hormone use, and personal characteristics in the changing prevalence and impact of menopause symptoms.

DESIGN

Annual longitudinal data were from Michigan Bone Health Study enrollees aged 24 to 44 years at baseline and followed up for a 10-year period beginning in 1992. In self-administered interviews, women reported the presence of and degree of bother (values from 1 = low to 8 = high) for symptoms related to sexuality, vasomotor, sleep/fatigue, negative mood, hair/skin, and urinary problems. Annually, collected sera samples were analyzed for estradiol, follicle-stimulating hormone, and testosterone concentrations.

RESULTS

Increasing age consistently predicted the development and bother of the measured symptoms. Transition to postmenopause and higher levels of follicle-stimulating hormone were significantly predictive only of the sexuality and vasomotor constructs, whereas higher estradiol levels were protective against increasing frequency and bother from sexuality and vasomotor constructs. Problems with sleeping, and secondarily, vasomotor symptoms, were the most bothersome constructs. Higher body mass index and current smoking behavior were highly related to increased bother with many symptom constructs, but especially vasomotor symptoms. Exogenous hormone use was associated with more bother from all symptom constructs.

CONCLUSIONS

Sexuality and vasomotor symptom constructs seem to be more related to menopause than other constructs. The frequency of other constructs in the pre-menopause and their very strong association with increasing age suggest caution in attributing these factors directly to neuroendocrine events of the menopause transition. The strong associations between smoking and body size with symptoms, particularly vasomotor symptoms, suggest that interventions directed at these personal characteristics might be effective in dampening their impact.

Age at natural menopause in a sample of Puerto Rican women

OBJECTIVES

To characterize the distribution of age at menopause in a sample of Puerto Rican women and to evaluate the differences in demographic, health and lifestyle factors associated with menopausal state.

BACKGROUND

Age at natural menopause may be an important marker of a woman's long-term risk of chronic disease. Understanding which factors influence the timing of menopause remains limited and while ethnic differences in age at menopause have been reported, little data are available for Puerto Rican women.

METHODS

In 2000, a self-administered questionnaire was completed by a sample of 300 women aged 30-59 attending health fairs in the cities of Carolina, Aguadilla and Yauco, Puerto Rico (PR). Data from this interview was used to determine age at menopause which was described with probit analysis. Women from different menopausal status groups were compared with respect to demographic, lifestyle and health characteristics by using contingency table analysis and chi-square statistics.

RESULTS

In a sample where 53% of women were menopausal, the median age of natural menopause was 51.4 years (95% confidence intervals 50.3-52.5). Compared to premenopausal women, naturally and surgically postmenopausal women had lower educational attainment, increased parity and were more likely to be obese (p < 0.05).

CONCLUSION

This analysis provides the first estimate of age at natural menopause among women living in PR and the age is similar to that reported in other populations. Determining whether this population tends to have an early or late menopause will facilitate a better understanding of the potential chronic disease profile of Puerto Rican women as they age.

Assessing menstrual cycles with urinary hormone assays

The Study of Women's Health Across the Nation (SWAN) is a multiethnic cohort study of middle-aged women enrolled at seven US sites. A subset of 848 women completed a substudy in which their urinary gonadotropins and sex steroid metabolites were assessed during one complete menstrual cycle or up to 50 consecutive days. Urine was analyzed for LH, FSH, estrone conjugates (E1c), and pregnanediol glucuronide (Pdg). To prepare for serial analysis of this large, longitudinal database in a population of reproductively aging women, we examined the performance of algorithms designed to identify features of the normal menstrual cycle in midreproductive life. Algorithms were based on existing methods and were compared with a "gold standard" of ratings of trained observers on a subset of 396 cycles from the first collection of Daily Hormone Substudy samples. In evaluating luteal status, overall agreement between and within raters was high. Only 17 of the 396 cycles evaluated were considered indeterminate. Of the 328 cycles rated as containing evidence of luteal activity (ELA), 320 were considered ELA by use of a Pdg threshold detection algorithm. Of 51 cycles that were rated as no evidence of luteal activity, only 2 were identified by this algorithm as ELA. Evaluation of the day of the luteal transition with methods that detected a change in the ratio of E1c to Pdg provided 85-92% agreement for day of the luteal transition within 3 days of the raters. Adding further conditions to the algorithm increased agreement only slightly, by 1-8%. We conclude that reliable, robust, and relatively simple objective methods of evaluation of the probability and timing of ovulation can be used with urinary hormonal assays in early perimenopausal women.

The risk for infant mortality among adolescent childbearing groups

OBJECTIVE

To evaluate risk disparities and risk factors for infant mortality among adolescent childbearing age groups.

METHODS

We combined the 1995 and 1996 comprehensive U.S. birth cohorts provided by the National Center for Heath Statistics. Our analysis included 777,762 singleton, first births to women aged 12-19 years linked to 4631 infant deaths. We used both bivariate comparisons and multivariable logistic regression for our analysis, with infant mortality as our main outcome measure.

RESULTS

Rates of infant mortality are substantially higher for < or =15-year-olds (8.1/1000 live births) compared with 16-17-year-olds (6.3/1000 live births) and 18-19-year-olds (5.4/1000 live births). Even after adjusting for risk factors associated with poor outcomes, including alcohol use, tobacco use, and prenatal care use, the risk for infant mortality was 1.6 (95% confidence interval [95% CI] 1.4, 1.7) times greater for infants of mothers < or =15 years old as compared with those mothers 18-19 years old. In the < or =15-year-old group, 62% of fathers were not reported on the child's birth certificate. Not reporting the father was associated with a 24% increased risk for infant mortality after adjusting for maternal and infant risk factors.

CONCLUSIONS

Childbearing in < or =15-year-olds is associated with a substantial increased risk for infant mortality compared with childbearing in older adolescence. This study suggests that not reporting the father on a birth certificate is a potential risk marker. Risk differences among adolescent age groups may be important to consider when creating tailored intervention and prevention strategies.

IGF-I, osteocalcin, and bone change in pregnant normotensive and pre-eclamptic women

Pre-eclampsia is a pregnancy disorder of uncertain etiology that affects 5-10% of all pregnancies, with symptoms typically presenting around or after 20 wk gestation. We hypothesized that IGF-I, osteocalcin, and bone loss would be different among women with pre-eclampsia compared with normotensive pregnant women. There were 962 pregnant healthy women, aged 12-35, who were assessed at entry to care, at 28 wk, and at delivery for osteocalcin and IGF-I concentrations. Bone ultrasound was measured at entry to care and at 6 wk postpartum, whereas bone mineral density was measured by dual x-ray densitometry at delivery. There were 64 women (6.7%) among the women being followed who developed pre-eclampsia. In women with pre-eclampsia, IGF-I concentrations were 74% greater in the third trimester compared with the first trimester, whereas there was little change in osteocalcin concentrations. In contrast, normotensive women had an average increase of 43% in IGF-I concentrations accompanied by a 63% decline in osteocalcin concentrations. In women with pre-eclampsia, IGF-I and osteocalcin concentrations were significantly correlated (r = 0.48 and 0.43) at both the first and third trimester time points, but only in the third trimester among normotensive women (r = 0.27). The bone change difference between the two groups was not statistically significant. Women with pre-eclampsia appear to have an exaggerated IGF-I responsiveness compared with women who are normotensive; however, the strong correlation between IGF-I and osteocalcin in women with pre-eclampsia suggests that the IGF-I is able to retain its role as a local regulator of bone remodeling, as indicated by the osteocalcin concentrations.

The association of menopause and physical functioning in women at midlife

OBJECTIVES

To determine whether the characteristics of menstrual bleeding and the menopausal transition are associated with physical functioning in women age 40 to 55, after considering ethnicity, ability to pay for basics, body size, and age.

DESIGN

Cross-sectional study.

SETTING

Seven geographically dispersed community samples in the United States.

PARTICIPANTS

The 14,427 respondents were Caucasians (46.9%), African Americans (28.7%), Chinese (4.0%), Japanese (5.3%), and Hispanics (12.6%) from the Study of Women's Health Across the Nation (SWAN) Cross-sectional Study, a study of the menopausal transition, including surgical menopause.

MEASUREMENTS

The dependent variable was a three-category variable based on the physical functioning scale of the Medical Outcomes Study. Explanatory variables included menstrual and menopausal status.

RESULTS

Eighty percent (80.8%) of women reported no limitation in physical functioning, whereas 10% of women had some limitation, and 9.2% of women indicated having substantial limitation. Women with substantial limitation in physical functioning had double the prevalence odds ratio (POR = 2.02; 95% confidence interval (CI) = 1.64-2.49) of having surgical menopause and 76% greater odds (POR = 1.76; 95% CI = 1.38-2.24)) of using hormones, compared with women with no limitation. Compared with those without limitation, women with substantial limitation in physical functioning had 56% greater odds (POR = 1.56; 95% CI = 1.23-1.97)) of being naturally postmenopausal and a 41% greater odds (POR = 1.41; 95% CI = 1.17-1.70) of being perimenopausal, relative to being premenopausal and after adjusting for other variables.

CONCLUSION

Even at the relatively early age of 40 to 55, approximately 20% of women self-reported limitation in physical functioning. Surgical menopause and the use of hormones were more frequently observed in women with some and substantial physical limitation than in women with no limitation, even after adjusting for economic status, age, body mass index, and race/ethnicity.

Maternal glucose concentration influences fetal growth, gestation, and pregnancy complications

Using 1990-1995 data, the authors examined the influence of post-challenge maternal glucose concentration on pregnancy outcome in 1,157 nondiabetic US gravidas. After control for potential confounding variables and comparing gravidas with lower glucose concentrations (<99 mg/dl) with the others, they found that mean birth weight increased by 50 g and 200 g with glucose concentrations of 99-130 mg/dl and >130 mg/dl, respectively. Increased maternal glucose concentration also was associated with an increased risk of large-for-gestation fetuses (p for trend < 0.001) and a decreased risk of fetal growth restriction (p for trend < 0.05). The association between glucose and gestation was inverse and significantly shortened when glucose concentrations were higher. Maternal complications increased twofold or more with high glucose concentrations and included cesarean section and clinical chorioamnionitis. Chorioamnionitis in combination with high maternal glucose concentration increased the risk of very preterm delivery almost 12-fold. These observations extend Pedersen's hypothesis-that high concentrations of maternal glucose give rise to increased nutrient transfer to the fetus and increase fetal growth, beyond the model of maternal diabetes (Acta Endocrinol 1954;16:330-42). They raise the question of whether higher, but seemingly normal maternal glucose concentration predisposes to or is a marker for placental inflammation and infection.

Epidemiology of risk factors for osteoarthritis: systemic factors

Osteoarthritis (OA) appears to be a mechanically driven but chemically mediated disease process in which there is attempted (or aberrant) repair. Well established risk factors for OA include aging, obesity, gender, and, in selected subgroups, congenital anomalies. This review addresses less well established risk factors for OA that can impact joints through their effect on systemic metabolism rather than their contribution to local joint geometry and structure. These systemic risk factors include obesity; bone and bone density; nutrients, particularly those that function as antioxidants; and genetic factors. There is great opportunity for new prevention and intervention strategies as we expand our understanding of the role of these systemic risk factors.

The experience of pain and emergent osteoarthritis of the knee

Discrepancies exist between radiographic osteoarthritis of the knee (OAK) and report of knee joint pain. Little is known about how these two definitions of osteoarthritis (OA) and their correlates differ between African American (AA) and Caucasian (CA) women.

OBJECTIVE

We compared the prevalence of radiographic OAK and knee joint pain in AA and CA women, and the congruency of these outcomes according to age, body size, and knee injury.

DESIGN

A cross-sectional study of African American and Caucasian women aged 40-53 years (N=829) in Southeast Michigan used the Kellgren and Lawrence Atlas of Standard Radiographs of Arthritis to characterize radiographs of both knee joints (weight bearing) and self-report of knee pain.

RESULTS

Current pain was a significantly more sensitive predictor of radiographic OAK among AA women (Se=0.51) compared to CA women (Se=0.35). Specificity was similar between AA women (Sp=0.77) and CA women (Sp=0.82). Positive predictive value was significantly greater for AA compared with CA women (PV+=0.40 and PV+=0.15, respectively). The odds of having radiographic OAK increased with BMI >32 kg/m(2) in both groups. Knee pain was related to BMI in CA women, but not AA women. Previous knee injury was associated with knee pain in both AA and CA women (OR=3.0 and OR=2.4).

CONCLUSIONS

Joint pain in AA women was more likely to be associated with radiographic OAK as compared with CA women. This suggests differences in these two groups in both how pain is experienced in the OAK process and in the prevalence of non-OAK related pain in knee joints.

Magnitude and variability of sequential estradiol and progesterone concentrations in women using depot medroxyprogesterone acetate for contraception

OBJECTIVE

To describe the magnitude and variability of sequential serum estradiol and progesterone concentrations throughout one depot medroxyprogesterone (DMPA) injection interval.

DESIGN

Prospective study.

SETTING

Family planning and women's health clinics.

PATIENT(S)

Thirty-one women, ages 19 to 46, using DMPA for contraception.

INTERVENTION(S)

Serum for estrogen and progesterone was collected weekly throughout one DMPA injection interval.

MAIN OUTCOME MEASURE(S)

Serum estradiol and progesterone concentrations; estradiol patterns produced from data plotted across the entire DMPA injection interval.

RESULT(S)

The average daily estradiol concentrations ranged from 7.9 to 69.1 pg/mL, with a mean of 18.9 +/- 12.9 and a median of 15.4 pg/mL. Average daily progesterone concentrations ranged from 0.14 to 1.1 ng/mL, with a mean of 0.40 +/- 0.19 ng/mL and a median of 0.36 ng/mL. Two general patterns of estradiol concentrations were identified. One pattern, observed in approximately one third of the participants, reflected estradiol concentrations that were extremely low (mean, 12.7 +/- 3.6 pg/mL; median, 13.4 pg/mL) and consistently flat across the DMPA injection interval. The second pattern, seen in the remaining participants, reflected estradiol concentrations that were higher (mean, 22.2 +/- 14.9 pg/mL; median, 17.3 pg/mL) and quite variable.

CONCLUSION(S)

This study demonstrated that estradiol concentrations were lower than the 40 to 50 pg/mL reported in most studies and, for the majority of women, varied substantially across the DMPA injection interval.

Osteoarthritis: new insights. Part 1: the disease and its risk factors

Osteoarthritis is the most common form of arthritis, affecting millions of people in the United States. It is a complex disease whose etiology bridges biomechanics and biochemistry. Evidence is growing for the role of systemic factors (such as genetics, dietary intake, estrogen use, and bone density) and of local biomechanical factors (such as muscle weakness, obesity, and joint laxity). These risk factors are particularly important in weight-bearing joints, and modifying them may present opportunities for prevention of osteoarthritis-related pain and disability. Major advances in management to reduce pain and disability are yielding a panoply of available treatments ranging from nutriceuticals to chondrocyte transplantation, new oral anti-inflammatory medications, and health education. This article is part 1 of a two-part summary of a National Institutes of Health conference. The conference brought together experts on osteoarthritis from diverse backgrounds and provided a multidisciplinary and comprehensive summary of recent advances in the prevention of osteoarthritis onset, progression, and disability. Part 1 focuses on a new understanding of what osteoarthritis is and on risk factors that predispose to disease occurrence. It concludes with a discussion of the impact of osteoarthritis on disability.

Bone mineral density in grand multiparous women with extended lactation

OBJECTIVE

We sought to assess whether the accumulation of multiple, frequent pregnancies and the accompanying repeated extended lactation events was a risk factor for low bone mineral density and osteoporosis.

STUDY DESIGN

The study population consisted of 30 grand multiparous women who had borne at least 6 children and lactated for at least 6 months with each child, as well as 6 nulliparous, premenopausal women from a population of Finnish American women associated with the Laestadian Church in Washington State. The Church membership has not embraced contraception or extensive bottle-feeding, resulting in a group of women who are either pregnant or lactating during most of their adult reproductive lives. The medical history included the delivery date, birth outcome, infant birth weight, and number of months lactated for each pregnancy, as well as other health information. Bone mineral density of the lumbar spine, femoral neck, and radius was measured with the Hologic QDR 4500-C dual-energy x-ray absorptiometry scanner. Proc Genmod, SAS version 6.14 (Statistical Analysis Systems, Inc, Cary, NC), was used to perform a Wilcoxon test for a nonparametric analysis of covariance and significance adjusted for age and body size.

RESULTS

The 2 study groups did not differ in terms of body mass index, history of smoking, or family history of osteoporosis and fracture, although the parous group was, on average, 8 years older than the nulliparous group (P <.05). The accumulation of repeated pregnancy and lactation events without a recovery interval was not associated with lowered bone mineral density or the presence of osteoporosis or osteopenia.

CONCLUSIONS

This study suggests that bone mineral density levels can be sustained in the presence of the rapidly changing hormone environment associated with multiple pregnancies accompanying lactation events without a "recovery" interval.

Functional status and hearing impairments in women at midlife

OBJECTIVES

The aim of this study was to address the prevalence of clinically assessed high-frequency hearing impairment (HFHI) and self-reported hearing impairment (SRHI) and examine the association of these hearing assessments with physical and mental functioning in African American and Caucasian women at midlife.

METHODS

The sample included 467 women who participated in the Michigan Functioning Substudy of the Study of Women's Health Across the Nation. Outcomes examined were physical and mental functioning from the Medical Outcomes Trust SF-12 Health Survey. HFHI was defined as threshold averages of 25 dB or greater over 4000, 6000, and 8000 Hertz.

RESULTS

Prevalence of unilateral HFHI was 26.6% (n = 68), and prevalence of bilateral HFHI was 12.0% (n = 56). Prevalence of SRHI was 16.7% (n = 78), with minimal overlap between HFHI and SRHI (n = 36). In multiple variable logistic regression analyses, HFHI in one ear only was not associated with physical or mental functioning and bilateral HFHI was associated with limited mental functioning only. SRHI was associated with limited physical and mental functioning.

DISCUSSION

Poor correlation of HFHI and SRHI in this population, combined with the significant association of SRHI with both measures of functioning, indicates that the two methods may be measuring different aspects of impairment. SRHI may facilitate early identification of individuals with hearing-related functional limitations.

Radiographically defined osteoarthritis of the hand and knee in young and middle-aged African American and Caucasian women

Osteoarthritis (OA) has been characterized as a slowly evolving degenerative disease affecting cartilage and bone, with a multifactorial etiology that may differ depending on the joint site. Because OA has been considered a disease of the elderly, few population-based studies have examined its frequency and characteristics in persons under the age of 45.

OBJECTIVE

In this cross-sectional study, we examined X-rays of both knees and the dominant hand in a population of younger black and white pre- and perimenopausal women in southeastern Michigan (N = 1053) for evidence of osteoarthritis, and reported these outcomes according to the risk factors of age, body size, injury, and smoking behavior.

DESIGN

Sixteen joints of the dominant hand as well as both knee joints (weight bearing) were evaluated using the Kellgren and Lawrence Atlas of Standard Radiographs of Arthritis.

RESULTS

By age 40, radiographically-defined osteoarthritis emerges in both the hands and knees. These age characteristics are observed in both black and white women, however prevalence of knee OA was higher in black females (23.1%) compared with white females (8.5%), and although prevalence of hand OA was more comparable between black (25.5%) and white females (19.2%), the joint sites affected differed. The major risk factors reported in studies of older populations are present in this younger population where OA is newly emerging.

CONCLUSIONS

This study provides strong evidence that primary prevention of OA must be implemented in young adulthood to curtail the emergence of radiographically-defined OA at the mid-life.

Semiparametric regression for periodic longitudinal hormone data from multiple menstrual cycles

We consider semiparametric regression for periodic longitudinal data. Parametric fixed effects are used to model the covariate effects and a periodic nonparametric smooth function is used to model the time effect. The within-subject correlation is modeled using subject-specific random effects and a random stochastic process with a periodic variance function. We use maximum penalized likelihood to estimate the regression coefficients and the periodic nonparametric time function, whose estimator is shown to be a periodic cubic smoothing spline. We use restricted maximum likelihood to simultaneously estimate the smoothing parameter and the variance components. We show that all model parameters can be easily obtained by fitting a linear mixed model. A common problem in the analysis of longitudinal data is to compare the time profiles of two groups, e.g., between treatment and placebo. We develop a scaled chi-squared test for the equality of two nonparametric time functions. The proposed model and the test are illustrated by analyzing hormone data collected during two consecutive menstrual cycles and their performance is evaluated through simulations.

Genetic markers, bone mineral density, and serum osteocalcin levels

We evaluated five genetic markers for products that contribute to skeletal mineralization including the Sp1 polymorphism for type I collagen Ai (COLIA1), the vitamin D receptor (VDR) translation initiation site polymorphism, the promoter of the osteocalcin gene containing a C/T polymorphism, the estrogen receptor (ER) gene containing a TA repeat, and the polymorphic (AGC)n site in the androgen receptor. These markers were evaluated for their potential relationship with bone mineral density (BMD), measured by dual-energy X-ray densitometry, or its 3-year change. Additionally, potential associations of these genotypes and with baseline osteocalcin concentration or its 3-year change (assessed using radioimmunoassay) were evaluated. The study was conducted in 261 pre- and perimenopausal women of the Michigan Bone Health Study, a population-based longitudinal study of musculoskeletal characteristics and diseases. The polymorphic (AGC)n site in the androgen receptor showed a strong association with BMD of the femoral neck (FN) and lumbar spine and remained highly significant after adjusting for body mass index (BMI), oophorectomy/hysterectomy, oral contraceptive (OC) use and hormone replacement use (p < 0.001). The TA repeat at the 5' end of the ER gene was associated with total body calcium (p < 0.05) after adjusting for BMI, oophorectomy and hysterectomy, and OC use. The frequency of oophorectomy and hysterectomy within selected genotypes explained much of the statistically significant association of the ER genotypes with BMD of the FN and spine. There was no association of measures of BMD or bone turnover with the Sp1 polymorphism for COLIA1, the VDR translation initiation site polymorphism, or the C/T promoter polymorphism of the osteocalcin gene. These findings suggest that sex hormone genes may be important contributors to the variation in BMD among pre- and perimenopausal women.

Vitamins and arthritis. The roles of vitamins A, C, D, and E

There are at least four mechanisms whereby the nutrient vitamins A, C, D, and E may be related to the processes that impede or give rise to OA. These nutrient vitamins have major roles in modulating oxidative stress, participating in immune responses, and contributing to cell differentiation. There is a substantial need to understand the contribution of these nutrients to OA, because they may provide important insight into ameliorating the initiation and progression of the disease. Simultaneously, greater understanding will add rationality to an area of potential intervention that is often based on anecdote. Investigation will be complex; there is the need to select appropriate systems. Typical animal model systems used in the study of OA are inappropriate because most animals can synthesize ascorbic acid. There is the need to disaggregate, as much as possible, the numerous subsets of OA and the plethora of processes that contribute to that heterogeneity. Certainly, there is the need to recognize the interdependency of the actions of each of these nutrients at the cellular level. Furthermore, humans rarely consume these nutrients as independent products. For example, watermelon is a primary source of both ascorbic acid and beta-carotene. Failure to address these complexities denies the scientist the opportunity to advance our understanding of health and disease processes. More importantly, failure to address these complexities denies the person with OA the opportunity to address his or her own health.

The associations of bone mineral density and bone turnover markers with osteoarthritis of the hand and knee in pre- and perimenopausal women

OBJECTIVE

To determine whether Caucasian women ages 28-48 years with newly defined osteoarthritis (OA) would have greater bone mineral density (BMD) and less bone turnover over time than would women without OA.

METHODS

Data were derived from the longitudinal Michigan Bone Health Study. Period prevalence and 3-year incidence of OA were based on radiographs of the dominant hand and both knees, scored with the Kellgren/Lawrence (K/L) scale. OA scores were related to BMD, which was measured by dual-energy x-ray absorptiometry, and to serum osteocalcin levels, which were measured by radioimmunoassay.

RESULTS

The period prevalence of OA (K/L grade > or =2 in the knees or the dominant hand) was 15.3% (92 of 601), with 8.7% for the knees and 6.7% for the hand. The 3-year incidence of knee OA was 1.9% (9 of 482) and of hand OA was 3.3% (16 of 482). Women with incident knee OA had greater average BMD (z-scores 0.3-0.8 higher for the 3 BMD sites) than women without knee OA (P < 0.04 at the femoral neck). Women with incident knee OA had less change in their average BMD z-scores over the 3-year study period. Average BMD z-scores for women with prevalent knee OA were greater (0.4-0.7 higher) than for women without knee OA (P < 0.002 at all sites). There was no difference in average BMD z-scores or their change in women with and without hand OA. Average serum osteocalcin levels were lower in incident cases of hand OA (>60%; P = 0.02) or knee OA (20%; P not significant). The average change in absolute serum osteocalcin levels was not as great in women with incident hand OA or knee OA as in women without OA (P < 0.02 and P < 0.05, respectively).

CONCLUSION

Women with radiographically defined knee OA have greater BMD than do women without knee OA and are less likely to lose that higher level of BMD. There was less bone turnover among women with hand OA and/or knee OA. These findings suggest that bone-forming cells might show a differential response in OA of the hand and knee, and may suggest a different pathogenesis of hand OA and knee OA.

Complex relation between increasing fat mass and decreasing high density lipoprotein cholesterol levels: evidence from a population-based study of premenopausal women

High density lipoprotein (HDL) cholesterol levels can be used to predict cardiovascular disease risk in women. To better understand variability in HDL cholesterol levels, the authors examined the relation with three domains (body size and type, sex hormone status, and carbohydrate metabolism) in a cross-sectional population-based 1993-1994 study of 402 premenopausal women from Tecumseh, Michigan. They found that these domains explained 27% of the total variation in HDL cholesterol levels; waist-to-hip ratio was the term that explained the highest proportion of variability (6% after fat mass, sex hormone binding globulin, and insulin levels were added to the model). In analyses restricted to women whose body mass index was > or = 32 kg/m2, which constituted 19% of this population, neither body mass index nor fat mass was a significant predictor of variability in HDL cholesterol levels. Significant variables were insulin levels, waist-to-hip ratio, and smoking. This finding suggests that there is a saturation of the relation between increasing fat mass and lower HDL cholesterol levels, as evidenced by the lack of a relation between the two among the heaviest women. Meanwhile, among the heaviest women, increasing insulin levels and a higher waist-to-hip ratio remained predictors of low levels of HDL cholesterol.

The reproducibility of ultrasound bone measures in a triethnic population of pregnant adolescents and adult women

We used bone ultrasound technology with its measurement of attenuation (broadband ultrasound attenuation [BUA] as dB/MHz) and sound velocity (speed of sound as m/s) for assessing the quantitative ultrasound index (QUI) summary measure in a triethnic population of 280 pregnant women. The study purpose was to describe the reproducibility of the ultrasound technology and determine if the correlations of age, weight, and ethnicity with the bone status measures in this population are consistent with the correlations of age, weight, and ethnicity that have been reported with other technologies that measure bone mass. We evaluated the first 280 women enrolled in our longitudinal study of lead turnover from maternal bone during pregnancy and lactation. Enrollees were pregnant, aged 12-29 years, and self-classified as black, white, or Hispanic. Bone ultrasound was measured twice at entry to prenatal care, which, on average, was at 14 weeks gestation. Reproducibility was described with intraclass correlations and the standard error of measurement. Age, weight, and ethnicity were associated with bone status measures using Spearman correlations and generalized linear models. The reproducibility of the summary bone measure, QUI, was high (96-97%). Variation in age and ethnicity did not alter reproducibility; however, the reproducibility of the attenuation measure (BUA as dB/MHz) lessened with increasing weight, declining from 95% to 89%. Since this attenuation is included in the summary QUI measure, there was a slight, and nonsignificant, decline in QUI reproducibility (from 97% to 96%) as women increased in size. There were no statistically significant differences in mean bone ultrasound measures according to age, where ages ranged from 12-29 years. Women who categorized themselves as black had, on average, an 8.5% greater QUI than did women who classified themselves as Hispanic or white. There were no significant pair-wise differences in mean ultrasound measures of bone between women classifying themselves as Hispanic or white. The use of ultrasound is a highly reproducible measure to assess bone characteristics in a population of pregnant adolescent and young adult women and its summary measure of bone mass is correlated with ethnic as well as body size characteristics.

Urinary ovarian and gonadotropin hormone levels in premenopausal women with low bone mass

We hypothesized that lower ovarian and gonadotropin hormone concentrations would be associated with lower levels of peak bone mineral density (BMD) in apparently normally menstruating women who did not exercise intensively and did not report anorexia or bulimia. This hypothesis was evaluated using a case-with-control study design (n = 65) which was nested within a population-based longitudinal study of peak bone mass (Michigan Bone Health Study) with annual assessment in women aged 25-45 years (n = 582). Cases were 31 premenopausal women with BMD of the lumbar spine, femoral neck, and total body less than the 10th percentile of the distribution, where controls were 34 premenopausal women with BMD between the 50th and 75th percentile. BMD was measured by dual-energy X-ray absorptiometry. In addition to their annual measurement, these 65 participants collected first-voided morning urine specimens daily through two consecutive menstrual cycles. The urine from alternating days of this collection was analyzed for estrone-3-glucuronide (E1G), pregnanediol glucuronide (PdG), testosterone, and follicle-stimulating hormone by radioimmunoassay and these values adjusted for daily creatinine excretion levels. Additionally, analyses of daily urine specimens for luteinizing hormone (uLH) was undertaken to better characterize the possible uLH surge. Cases had significantly lower amounts of E1G (p = 0.009) and PdG (p = 0.002) than did controls, whether amounts were characterized by a mean value, the highest value, or the area under the curve, and after statistically controlling for body size. Further, when B-splines were used to fit lines to the E1G and PdG data across the menstrual cycle, the 95% confidence intervals (CIs) about the line for the controls consistently excluded and excluded and exceeded the 95% confidence bands for the cases in the time frame associated with the luteal phase in ovulatory cycles. Likewise, 95% CIs for the LH surge in controls exceeded the fitted line for cases around the time associates with the LH surge. The cases and controls were not different according to dietary intake (energy, protein, calcium), family history of osteoporosis, reproductive characteristics (parity, age at menarche, age of first pregnancy), follicular phase serum hormone levels, calciotropic hormone levels, or by evidence of perimenopause. We conclude that these healthy, menstruating women with BMD at the lowest 10th percentile from a population-based study had significantly lower urinary sex steroid hormone levels during the luteal phase of menstrual cycles as compared with hormone levels in premenopausal women with BMD between the 50th and 75th percentile of the same population-based study, even after considering the role of body size. These data suggest that subclinical decreases in circulating gonadal steroids may impair the attainment and/or maintenance of bone mass in otherwise reproductively normal women.

Bone mineral density and its change in pre-and perimenopausal white women: the Michigan Bone Health Study

There is a need to better understand potential bone mineral density (BMD) loss during the menopausal transition since this period may include the initiation of interventions. The study purpose was to determine if there was BMD loss at the femoral neck, lumbar spine, or total body bone sites in a population-based study of women approaching or transitioning the midlife. The 583 enrollees were 25-45 years of age at the first of four annual measurements from 1992 through 1996. Bone mineral content and bone width were measured using dual-energy X-ray absorptiometry. Considering all enrollees collectively, there was a significant 3-year decline (1%) in BMD at the femoral neck over the 3-year period (p = 0.076). There was no significant annual change in the lumbar spine (p = 0.11), and a significant annual increase in the total body BMD (p = 0.0003). Within subgroups and cross-sectionally, BMD values of the femoral neck were 5% lower in women classified as perimenopausal compared with premenopausal enrollees; BMD was 3% and 1% lower at the lumbar spine and total body site, respectively. Longitudinally, among perimenopausal women, a double oophorectomy was associated with BMD loss in the spine (p = 0.0003), even though 75-85% of these women had a hormone replacement prescription at some time during the study period. In summary, the site with evidence of loss was the femoral neck, specifically among perimenopausal women. There was little evidence of substantial total body or lumbar spine BMD loss in premenopausal women with ovaries who maintained follicle-stimulating hormone levels < 20 mIU/l in the early follicular period. Double oophorectomy, even with hormone replacement, was associated with bone loss.

Bone mineral density and its change in white women: estrogen and vitamin D receptor genotypes and their interaction

Low bone mineral density (BMD) is a major risk factor for development of osteoporosis; increasing evidence suggests that attainment and maintenance of peak bone mass as well as bone turnover and bone loss have strong genetic determinants. We examined the association of BMD levels and their change over a 3-year period, and polymorphisms of the estrogen receptor (ER), vitamin D receptor (VDR), type I collagen, osteonectin, osteopontin, and osteocalcin genes in pre- and perimenopausal women who were part of the Michigan Bone Health Study, a population-based longitudinal study of BMD. Body composition measurements, reproductive hormone profiles, bone-related serum protein measurements, and life-style characteristics were also available on each woman. Based on evaluation of women, ER genotypes (identified by PvuII [n = 253] and XbaI [n = 248]) were significantly predictive of both lumbar spine (p < 0.05) and total body BMD level, but not their change over the 3-year period examined. The VDR BsmI restriction fragment length polymorphism was not associated with baseline BMD, change in BMD over time, or any of the bone-related serum and body composition measurements in the 372 women in whom it was evaluated. Likewise, none of the other polymorphic markers was associated with BMD measurements. However, we identified a significant gene x gene interaction effect (p < 0.05) for the VDR locus and PvuII (p < 0.005) and XbaI (p < 0.05) polymorphisms, which impacted BMD levels. Women who had the (-/-) PvuII ER and bb VDR genotype combination had a very high average BMD, while individuals with the (-/-) PvuII ER and BB VDR genotype had significantly lower BMD levels. This contrast was not explained by differences in serum levels of osteocalcin, parathyroid hormone, 1,25-dihydroxyvitamin D, or 25-dihydroxyvitamin D. These data suggest that genetic variation at the ER locus, singly and in relation to the vitamin D receptor gene, influences attainment and maintenance of peak bone mass in younger women, which in turn may render some individuals more susceptible to osteoporosis than others.

Interpregnancy weight retention patterning in women who breastfed

This study compares weight change in lactating women with an 18-month interpregnancy interval with woman who also breastfed but did not have an immediate subsequent pregnancy. Cases were women who breastfed an index infant for 6 months and subsequently became pregnant within 18 months (cases = 25), and the controls also breastfed an index infant for 6 months but had no ensuing pregnancy (controls = 20) within 18 months. The pattern of postpartum weight retention following the initial pregnancy was not statistically different in cases compared to the controls. However, following their ensuing subsequent pregnancy, cases were 1.3 kg heavier than their average weight after their baseline pregnancy (P = 0.02). The best predictor of this greater weight was their weight change during the interpregnancy interval (P = 0.03). Total weight gain during the gestational period of the subsequent pregnancy was not associated with the greater weight following the subsequent pregnancy. Likewise, estimates of the amount of energy as calories or physical activity levels were not significant predictors of this greater weight following the subsequent pregnancy. These findings suggest that monitoring of postpartum weight, even in breastfeeding women, is essential. These findings indicate that breastfeeding women begin the next postpartum interval weighing more than the amount observed in the initial postpartum period.

Role of calciotrophic hormones in calcium mobilization of lactation

The postpartum period can be a time when profound changes in calcium metabolism and bone mineral density (BMD) occur, particularly in association with lactation. We investigated the hypothesis that calciotrophic hormones [1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, and parathyroid hormone (PTH)] are different by lactation practice or hormone status [PTH-related peptide (PTHrP), estradiol, and prolactin] and have a potential role in the bone loss and recovery associated with lactation. 1,25-Dihydroxyvitamin D, 25-hydroxyvitamin D, PTH, femoral BMD, PTHrP, prolactin, estradiol, and bone turnover markers were measured at 2 wk and at 2, 4, 6, 12, and 18 mo postparturition in 115 postpartum women aged 20-40 y (parity: 0-1). Lumbar spine BMD was measured at 2 wk and at 6, 12, and 18 mo during the postpartum period. PTH, 1,25-dihydroxyvitamin D, and 25-hydroxyvitamin D concentrations were nonlinear across the 18-mo postpartum period. Between baseline and 18 mo postparturition, PTH and 1,25-dihydroxyvitamin D concentrations did not decline, while there was a substantial decline in 25-hydroxyvitamin D concentrations. PTH, 1,25-dihydroxyvitamin D, and 25-hydroxyvitamin D concentrations did not differ by lactation practice or by PTHrP, estradiol, or prolactin status. These classic calciotrophic hormones were not associated with concentrations of bone turnover markers or changes in BMD in lactating women. In summary, patterns of change in calciotrophic hormones (PTH, 1,25-dihydroxyvitamin D, and 25-hydroxyvitamin D) in the 18-mo postpartum period appeared to be independent of PTHrP, estradiol, prolactin, or lactation status and were not associated with bone turnover markers. These data do not support the hypothesis that these three calciotrophic hormones are a central part of the calcium mobilization associated with the bone loss of lactation.

Lactation and weight retention

The effect of lactation on weight retention was investigated longitudinally, with data collected at 0.5, 2, 4, 6, 12, and 18 mo after parturition in 110 women aged 20-40 y who had been nulliparous or primiparous. At each evaluation women were categorized as fully breast-feeding, partly breast-feeding, or bottle-feeding including infants weaned to a bottle (bottle feeding/weaned). Postpartum weight retention was calculated by subtracting weight before pregnancy from weight at each evaluation. Lactation practices were found to be significantly associated (P < 0.05) with postpartum weight retention by longitudinal regression analysis. Women who bottle-fed their infants retained more weight over time than women who breast-fed their infants. Significantly slower rates of weight loss were observed when women ceased breast-feeding or switched from fully to partly breast-feeding. Weight retention over time was greater in women who were older, unmarried, or had greater weight gain during pregnancy (P < 0.05). A pattern of weight gain rather than weight loss was observed in unmarried women. Our findings suggest that lactation influences the pattern of postpartum weight retention; however, the effect of lactation on weight retention was sufficiently limited to warrant minimal emphasis on lactation as a means of minimizing postpartum weight retention.

The menopause transition

New paradigms for the study of menopause will increase our understanding of whether symptoms, syndromes, and chronic diseases are associated with menopause. Rather than considering menopause as a discrete event, it has become clear that the menopause transition takes place over many years. Although this realization is central to our understanding of menopause, it is difficult to measure the temporal pattern of changes in hormones and their relation to concurrent or subsequent health-related events. The model of hormonal changes at the time of the transition has been expanded to include not only declines in estrogen but changes in a broader range of hormones, including the potential role of androgens. New models are attempting to account for the pattern and frequency of changes in hormone levels. Another level of complexity is contributed by the expansion of the menopause model to include comorbid medical and psychiatric conditions, environmental influences, and behaviors as covariates that influence the expression of menopause-related events. Although this more complicated paradigm makes the conduct of menopause research more challenging, it is also likely to elucidate previously confusing data, as the proper understanding of potentially complex exposures, effect modifiers, and confounders is more likely to provide clearer answers to critical research questions.

Clinical epidemiology and osteoporosis. Measures and their interpretation

Identifying patients with a high risk of fracture and monitoring a patient's therapeutic response are important. Current methods to evaluate the risk of fracture include the measurement of bone mineral density as well as other risk factors, including those associated with the risk of falling. Several considerations are important in defining the risk for fracture. There is currently no level of bone mineral density at which the risk of fracture is zero, that is, some high-risk women will not have a fracture and some low-risk women will. The monitoring of high-risk individuals for subtle changes in their bone status is not economically feasible at this time. Given the precision of current measurement technology, it is more reasonable to expect to monitor individuals on a 3- to 5-year basis rather than every 6 months to 1 year. There is no single optimal site at which measurement is highly precise and predictive of bone mineral density measurement at other skeletal locations. Currently, measurement of the femoral neck seems to have the most universal applicability. Measurement of bone turnover markers remains more effective as a research tool and is less effective as a method to diagnose or monitor the bone status of individual patients.

Parenteral zinc supplementation in adult humans during the acute phase response increases the febrile response

The acute phase response (APR) that follows injury or infection is characterized by a decrease in serum zinc concentrations, which we hypothesized benefits the host. Additionally, we proposed that preventing this decline by supplementing zinc would result in an exaggerated APR as indicated by elevated temperatures, increased serum cytokine concentrations, interleukin 6 and the acute phase protein (ceruloplasmin). A prospective, randomized, double-blinded, clinical trial was conducted. Patients on home parenteral nutrition with a diagnosis of catheter sepsis and patients with a diagnosis of pancreatitis, also on total parenteral nutrition (TPN), were recruited for the study. Following enrollment, block randomization was used to assign patients to receive 0 mg (n = 23) or 30 mg (n = 21) of zinc per day for the first 3 d of TPN. Blood samples for measurement of serum zinc, copper, ceruloplasmin and interleukin-6 were obtained upon enrollment and on d 1 through 3 of TPN. The highest temperatures reported on these days in the medical record were also recorded. Repeated measures ANOVA was used to determine differences in the primary outcome variables over time. No significant differences between groups were observed in serum interleukin-6 or ceruloplasmin concentrations. A significantly higher (P = 0.035) temperature was observed in the zinc-supplemented group compared with the control group on d 3 of parenteral nutrition. We conclude that parenteral zinc supplementation in patients experiencing a mild APR resulted in an exaggerated APR as evidenced by a significantly higher febrile response.