Association of prenatal folate status with early childhood wheeze and atopic dermatitis.

BACKGROUND: Prenatal folic acid supplementation is recommended to prevent birth defects. Some foods are fortified in the USA to ensure sufficient intake among reproductive-aged women. However, high prenatal folate exposure may be a risk factor for childhood atopic diseases. We investigated associations between prenatal folate and early childhood wheeze and atopic dermatitis in a US cohort. METHODS: We studied 858 mother-child dyads, enrolled prenatally. Folate was measured in 2nd and 3rd trimester maternal plasma. Parents reported current wheeze (previous 12 months) and healthcare provider diagnosis of atopic dermatitis at 3 years. We examined associations using logistic regression, modeling folate continuously and dichotomously (< or ≥20 ng/mL), a level often considered supraphysiologic. RESULTS: Over half of women were African American and on Medicaid. Median (interquartile range) folate levels were 22.6 (15.9-30.0) and 23.1 (16.1-30.0) ng/mL for 2nd and 3rd trimesters, respectively. Current wheeze and atopic dermatitis were reported for 20.4% and 26.8% of children, respectively. Second trimester folate as a continuous exposure was not significantly associated with outcomes. Decreased odds of current wheeze were observed in children born to mothers who had 2nd trimester folate ≥20 ng/mL (adjusted odds ratios = 0.67, 95% confidence interval = 0.46, 0.97) compared to children with maternal levels <20 ng/mL. Third trimester folate was not associated with outcomes. CONCLUSIONS: High plasma folate in mid-pregnancy was associated with decreased odds of current wheeze at age 3. Our findings do not support harmful effects of high prenatal folate levels on childhood atopic diseases in this setting.

Longitudinal changes in the dietary inflammatory index: an assessment of the inflammatory potential of diet over time in postmenopausal women.

BACKGROUND/OBJECTIVES: The dietary inflammatory index (DII) measured at one time point is associated with risk of several chronic diseases, but disease risk may change with longitudinal changes in DII scores. Data are lacking regarding changes in DII scores over time; therefore, we assessed changes in the DII in the Women's Health Initiative (WHI). SUBJECTS/METHODS: DII scores were calculated using data from repeated food frequency questionnaires in the WHI Observational Study (OS; n=76 671) at baseline and year 3, and the WHI Dietary Modification trial (DM; n=48482) at three time points. Lower DII scores represent more anti-inflammatory diets. We used generalized estimating equations to compare mean changes in DII over time, adjusting for multiple comparisons, and multivariable-adjusted linear regression analyses to determine predictors of DII change. RESULTS: In the OS, mean DII decreased modestly from -1.14 at baseline to -1.50 at year 3. In the DM, DII was -1.32 in year 1, -1.60 in year 3 and -1.48 in year 6 in the intervention arm and was -0.65 in year 1, -0.94 in year 3 and -0.96 in year 6 in the control arm. These changes were modified by body mass index, education and race/ethnicity. A prediction model explained 22% of the variance in the change in DII scores in the OS. CONCLUSIONS: In this prospective investigation of postmenopausal women, reported dietary inflammatory potential decreased modestly over time. Largest reductions were observed in normal-weight, highly educated women. Future research is warranted to examine whether reductions in DII are associated with decreased chronic disease risk.

Arterialized venous bicarbonate is associated with lower bone mineral density and an increased rate of bone loss in older men and women.

CONTEXT: Higher dietary net acid loads have been associated with increased bone resorption, reduced bone mineral density (BMD), and increased fracture risk. OBJECTIVE: The objective was to compare bicarbonate (HCO3) measured in arterialized venous blood samples to skeletal outcomes. DESIGN: Arterialized venous samples collected from participants in the Health, Aging and Body Composition (Health ABC) Study were compared to BMD and rate of bone loss. SETTING: The setting was a community-based observational cohort. PARTICIPANTS: A total of 2287 men and women age 74 ± 3 years participated. INTERVENTION: Arterialized venous blood was obtained at the year 3 study visit and analyzed for pH and pCO2. HCO3 was determined using the Henderson-Hasselbalch equation. MAIN OUTCOME MEASURE: BMD was measured at the hip by dual-energy x-ray absorptiometry at the year 1 (baseline) and year 3 study visits. RESULTS: Plasma HCO3 was positively associated with BMD at both year 1 (P = .001) and year 3 (P = .001) in models adjusted for age, race, sex, clinic site, smoking, weight, and estimated glomerular filtration rate. Plasma HCO3 was inversely associated with rate of bone loss at the total hip over the 2.1 ± 0.3 (mean ± SD) years between the two bone density measurements (P < .001). Across quartiles of plasma HCO3, the rate of change in BMD over the 2.1 years ranged from a loss of 0.72%/y in the lowest quartile to a gain of 0.15%/y in the highest quartile of HCO3. CONCLUSIONS: Arterialized plasma HCO3 was associated positively with cross-sectional BMD and inversely with the rate of bone loss, implying that systemic acid-base status is an important determinant of skeletal health during aging. Ongoing bone loss was linearly related to arterialized HCO3, even after adjustment for age and renal function. Further research in this area may have major public health implications because reducing dietary net acid load is possible through dietary intervention or through supplementation with alkaline potassium compounds.

Ethnic differences in the relationship between birth weight and type 2 diabetes mellitus in postmenopausal women.

AIM: The objective of this study is to examine the relationship between self-reported birth weight and the adult occurrence of type 2 diabetes mellitus in a large multi-ethnic population of women. METHODS: Baseline data from the Women's Health Initiative Observational Study [n=75,993] was used to examine the association between participant birth weight category and prevalent type 2 diabetes mellitus. Models were adjusted for age, ethnicity, body mass index and other pertinent risk factors. Sub-analyses were performed stratifying by ethnicity. RESULTS: There was a strong inverse association between birth weight and type 2 diabetes mellitus with a birth weight of <6 pounds (lbs) (OR: 1.16, 95% CI: 1.01, 1.33) significantly associated with an increased risk of type 2 diabetes mellitus and a birth weight of ≥10 lbs (OR: 0.72, 95% CI: 0.57, 0.92) associated with a decreased risk of type 2 diabetes mellitus compared to women who reported their birth weight between 7 and 8 lbs 15 ounces (oz). Stratifying by ethnicity, the inverse association between birth weight and type 2 diabetes mellitus was only apparent in White women, but not Black, Hispanic or Asian women. CONCLUSION: Lower birth weight was associated with increased T2D risk in American White and Black post-menopausal women.

Body esteem, peer difficulties and perceptions of physical health in overweight and obese urban children aged 5 to 7 years.

OBJECTIVE: To determine whether there is an association between body mass index (BMI) and body esteem in young overweight and obese urban children, and to test peer relationship difficulties and perceived physical health as mediators of this relationship. METHODS: Child self-reported body esteem, and parent-reported child peer relationship difficulties (being bullied by peers and peer rejection) and physical health perceptions were obtained from 218 overweight and obese children aged 5-7 years (81% racial/ethnic minority, M BMI = 25.3) and their primary caregivers. RESULTS: Higher BMI was associated with lower body esteem for both girls and boys. This relation was mediated by poor physical health for boys but not for girls. Peer relationship difficulties did not mediate the observed association between BMI and body esteem in either group; however, girls with higher BMI experienced more bullying and being bullied by peers was associated with lower body esteem in girls. CONCLUSIONS: Intervening with perceptions of physical health may buffer overweight and obese boys from developing low body esteem in early childhood.

Dietary patterns, insulin sensitivity and inflammation in older adults.

BACKGROUND/OBJECTIVES: Several studies have linked dietary patterns to insulin sensitivity and systemic inflammation, which affect risk of multiple chronic diseases. The purpose of this study was to investigate the dietary patterns of a cohort of older adults, and to examine relationships of dietary patterns with markers of insulin sensitivity and systemic inflammation. SUBJECTS/METHODS: The Health, Aging and Body Composition (Health ABC) Study is a prospective cohort study of 3075 older adults. In Health ABC, multiple indicators of glucose metabolism and systemic inflammation were assessed. Food intake was estimated with a modified Block food frequency questionnaire. In this study, dietary patterns of 1751 participants with complete data were derived by cluster analysis. RESULTS: Six clusters were identified, including a 'healthy foods' cluster, characterized by higher intake of low-fat dairy products, fruit, whole grains, poultry, fish and vegetables. In the main analysis, the 'healthy foods' cluster had significantly lower fasting insulin and homeostasis model assessment of insulin resistance values than the 'breakfast cereal' and 'high-fat dairy products' clusters, and lower fasting glucose than the 'high-fat dairy products' cluster (P≤0.05). No differences were found in 2-h glucose. With respect to inflammation, the 'healthy foods' cluster had lower interleukin-6 than the 'sweets and desserts' and 'high-fat dairy products' clusters, and no differences were seen in C-reactive protein or tumor necrosis factor-α. CONCLUSIONS: A dietary pattern high in low-fat dairy products, fruit, whole grains, poultry, fish and vegetables may be associated with greater insulin sensitivity and lower systemic inflammation in older adults.

Dietary fat and cholesterol and risk of cardiovascular disease in older adults: the Health ABC Study.

BACKGROUND AND AIMS: Although dietary fats and cholesterol have previously been associated with risk of cardiovascular disease (CVD) in middle-aged populations, less is known among older adults. The purpose of this study was to determine the association between dietary fats, cholesterol, and eggs and CVD risk among community-dwelling adults aged 70-79 in the Health, Aging and Body Composition Study. METHODS AND RESULTS: Diet was assessed using an interviewer-administered 108-item food frequency questionnaire (n=1941). CVD events were defined as a confirmed myocardial infarction, coronary death, or stroke. Relative rates of CVD over 9 years of follow-up were estimated using Cox proportional hazards models. During follow-up, there were 203 incident cases of CVD. There were no significant associations between dietary fats and CVD risk. Dietary cholesterol (HR (95% CI): 1.47 (0.93, 2.32) for the upper vs. lower tertile; P for trend, 0.10) and egg consumption (HR (95% CI): 1.68 (1.12, 2.51) for 3+/week vs. <1/week; P for trend, 0.01) were associated with increased CVD risk. However, in sub-group analyses, dietary cholesterol and egg consumption were associated with increased CVD risk only among older adults with type 2 diabetes (HR (95% CI): 3.66 (1.09, 12.29) and 5.02 (1.63, 15.52), respectively, for the upper vs. lower tertile/group). CONCLUSIONS: Dietary cholesterol and egg consumption were associated with increased CVD risk among older, community-dwelling adults with type 2 diabetes. Further research on the biological mechanism(s) for the increased CVD risk with higher dietary cholesterol and frequent egg consumption among older adults with diabetes is warranted.

Dietary factors in relation to daily activity energy expenditure and mortality among older adults.

OBJECTIVES: To examine the association between dietary factors to daily activity energy expenditure (DAEE) and mortality among older adults. DESIGN AND SETTING: A sub-study of Health, Aging, and Body Composition study. PARTICIPANTS: 298 older participants (aged 70-82 years) in the Health, Aging, and Body Composition Energy Expenditure sub-study. MEASUREMENTS: Dietary factors, DAEE, and all-cause mortality were measured in 298 older participants. Dietary factors include dietary intake assessed by the Block Food Frequency Questionnaire (FFQ), Healthy Eating Index (HEI), and self-reported appetite and enjoyment of eating. DAEE was assessed using doubly labeled water. All-cause mortality was evaluated over a 9 year period. RESULTS: Participants in the highest tertile of DAEE were more likely to be men and to report having a 'good' appetite; BMI among men, proportion married, IL-6 and CRP levels and energy intake were also higher. Fewer black participants were in the 'good' HEI category. Participants in the 'good' HEI category had higher cognitive scores and a higher education level. Participants who reported improvement in their appetite as well as participants who reported a 'good' appetite were at lower risk for mortality (HR (95% CI): 0.42 (0.24-0.74) and 0.50 (0.26-0.88), respectively) even after adjusting for DAEE, demographic, nutritional and health indices. CONCLUSIONS: We showed an association between DAEE and appetite and mortality among well-functioning, community-dwelling older adults. These findings may have some practical use for the health providers. Inclusion of a question regarding appetite of an elderly patient may provide important information regarding risk for health deterioration and mortality.

The association between weight history and physical performance in the Health, Aging and Body Composition study.

OBJECTIVE: Although the association between current obesity and physical disability is well known, the cumulative effect of obesity is unknown. Using data from the Health, Aging and Body Composition study, we examined the association between weight history in young and middle adulthood and weight status in late adulthood with physical performance in late adulthood. DESIGN: Longitudinal cohort study. SUBJECTS: White and black men and women aged 70-79 years at study baseline (n=2803). MEASURES: Body mass index (BMI; kg/m(2)) was calculated using recalled height at age 25 and weight at age 25 and 50 and measured height and weight at ages 70-79. Physical performance at ages 70-79 was assessed using a short physical performance battery (SPPB) and a 400-m walk test. RESULTS: In this well-functioning cohort, approximately 24% of men and 8% of women reported being overweight or obese (BMI > or =25 kg/m(2)) at age 25, 51% of men and 37% of women reported being overweight or obese at age 50, and 69% of men and 66% of women were overweight or obese at ages 70-79. Men and women who were obese (BMI > or =30 kg/m(2)) at ages 25, 50 and 70-79 had significantly worse SPPB scores and 400-m walk times than those who were normal weight. Women who were overweight (BMI 25-29.9 kg/m(2)) at ages 25, 50 and 70-79 also had significantly worse physical performance. Furthermore, men and women who had a history of being overweight or obese at ages 25 or 50 had worse physical performance compared to those who were normal weight throughout or who were overweight or obese at ages 70-79 but not in midlife or earlier. CONCLUSIONS: Maintaining a healthy body weight throughout adulthood may play a role in preventing or delaying the onset of physical disability.

Cognitive ability is associated with suspected reporting errors on food frequency questionnaires.

OBJECTIVE: To examine potential for bias in reported total energy intake on a Food Frequency Questionnaire (FFQ) among older adults. DESIGN: Longitudinal cohort study. SUBJECTS/SETTING: 2,706 Community-dwelling Black and White older adults, aged 70-79 years, enrolled in the Health, Aging, and Body Composition study. Multivariate logistic regression analyses were conducted with potential errors on reported total energy intake on the Food Frequency Questionnaire (FFQ) as the outcome variable and with cognitive ability, measured by the Modified Mini Mental State Exam (3MS) as the primary independent variable. The regression model controlled for site, race, gender, age, body size, and physical activity. Separate models were fit using 3MS as a continuous variable and for multiple 3MS cutpoints. All models revealed similar findings. RESULTS: Cognitive ability was inversely associated with potential errors in reporting total energy intake, whereby a five-point increase in 3MS scores was associated with a 14% decreased likelihood of reporting errors (Odds Ratio=0.86, 95% Confidence Interval: 0.77, 0.95). Additionally, compared to White women, White men were 2 times more likely, and Black women and Black men were 3 times more likely, to have errors in reporting total energy intake. CONCLUSION: This study provides evidence that for older adults, lower cognition scores are associated with increased potential errors in reporting total energy intake. APPLICATIONS: Dietary reporting from older adults may be inaccurate due to cognitive deficits. A brief assessment of cognitive function may assist clinicians in dietary evaluations and recommendation and may benefit studies using FFQ data where the measure of cognitive function could be utilized to stratify data analyses and conduct sensitivity analyses.

Low subcutaneous thigh fat is a risk factor for unfavourable glucose and lipid levels, independently of high abdominal fat. The Health ABC Study.

AIMS: We investigated whether low subcutaneous thigh fat is an independent risk factor for unfavourable glucose and lipid levels, and whether these associations differ between sexes, and between white and black adults. Our secondary aim was to investigate which body composition characteristics (lean tissue, fat tissue) are reflected by anthropometric measures (waist and thigh circumference). METHODS: Anthropometric measurements and computed tomography of the abdomen and of the thigh were performed for all participants of the Health, Aging and Body Composition Study, who were aged 70-79 years. Fasting glucose, triglycerides and HDL-cholesterol, and 2-h postload glucose were determined. RESULTS: After excluding those already diagnosed with diabetes or dyslipidaemia, we analysed data from 2,106 participants. After adjustment for abdominal subcutaneous and visceral fat, and intermuscular thigh fat, larger thigh subcutaneous fat area was statistically significantly associated with lower ln-transformed triglycerides [standardised beta (95% CI) -0.12 (-0.20 to -0.04) in men and -0.13 (-0.21 to -0.05) in women] and higher ln-HDL-cholesterol [0.10 (0.02 to 0.19) and 0.09 (0.01 to 0.18), respectively]. The associations with lower glucose levels were strong in men [-0.11 (-0.20 to -0.02) for fasting and -0.14 (-0.23 to -0.05) for postload glucose], but not statistically significant in women [-0.02 (-0.10 to 0.07) and -0.04 (-0.13 to 0.05), respectively]. There were no differences in the associations between white and black persons. Waist circumference was more strongly associated with abdominal subcutaneous fat, and this association became stronger with increasing BMI, whereas the association with visceral fat became weaker. Thigh circumference was equally dependent on thigh fat and thigh muscle in men, whereas in women the fat component was the main contributor. CONCLUSION: Larger subcutaneous thigh fat is independently associated with more favourable glucose (in men) and lipid levels (in both sexes) after accounting for abdominal fat depots, which are associated with unfavourable glucose and lipid levels. Anthropometric measures reflect different fat depots at different levels of BMI at the abdomen, and reflect both fat and lean tissue at the thigh. These results emphasise the importance of accurate measures of regional body composition when investigating potential health risks.

Appendicular fractures: a significant problem among institutionalized adults with developmental disabilities.

A high incidence of nontraumatic fracture in adults with developmental disabilities living in a state-run facility was described. Risk factors for fracture, including bone mineral density (BMD), were investigated to determine whether people at highest risk for fracture could be prospectively identified. There was a 7.3% incidence of fracture among 391 adults. Risk factors were examined for 23 residents with fracture and 23 age-, race-, and gender-matched controls. There was a trend for antiepileptic medication usage to be associated with fractures. Estimated BMD by heel ultrasound did not predict fracture; however, values were much lower than those for the general population. Fractures and low BMD are significant problems among institutionalized adults with severe developmental disabilities. Further studies to identify therapies to prevent fractures are warranted.

Bone density in Ehlers-Danlos syndrome.

Ehlers-Danlos Syndrome (EDS) is the most common inherited disorder of connective tissue recognized. The objectives of the present study were to determine bone mineral density (BMD) and biochemical markers of bone metabolism in EDS. Twenty-three subjects with Type III EDS and 23 matched controls underwent BMD measurement by dual-Energy X-ray absorptiometry (DXA) of the lumbar spine and femoral neck. Health history questionnaires and biochemical markers of bone and connective tissue metabolism were also assessed. No significant differences in BMD at the lumbar spine or differences in biochemical markers of bone and connective tissue metabolism were found between EDS subjects and controls. EDS subjects had a significantly decreased BMD at the femoral neck compared with controls, but this difference disappeared after adjustment for body height, weight and physical activity levels.

The role of collagen abnormalities in ultrasound and densitometry assessment: In vivo evidence.

There is little information concerning how the mutation of collagen affects bone mineralization and the assessment of bone properties. To estimate these influences, we performed ultrasonic assessments of the calcaneus and bone mineral density (BMD) measurements of the hip and lumbar spine. Females with diseases related to the mutation of collagen [Ehlers-Danlos syndrome (EDS) type III and systemic sclerosis (SSc)] participated in this study. We compared the broadband ultrasound attenuation (BUA and UBI-4), the average transit time through the heel (TTH), and a multiple factor index (UBI-4T) with control subjects matched on age, race, and menstrual status. Both groups of patients had BMD of the spine (L2-L4) within the normal range for their age and sex (for EDS: n = 23, 1.14 +/- 0. 14 g/cm2 and z-score = 0.37; for SSc: n = 15, 0.98 +/- 0.15 g/cm2 and z-score = 0.20). EDS and SSc subjects had lower BMD of the femoral neck (FN) compared with controls (for EDS: 0.91 +/- 0.13 g/cm2, z-score = -0.41, P = 0.025; for SSc 0.67 +/- 0.13 g/cm2, z-score = -0.92, P = 0.006). Subjects with EDS and SSc also had lower BUA values (P = 0.051-0.001) compared with controls. After adjusting for body weight, height, and the level of physical activity, the difference in FN BMD between EDS or SSc and controls became marginal (EDS: P = 0.072; SSc: P = 0.086). However, the significant difference for BUA between subjects and controls remained for EDS (P = 0.008), and disappeared for SSc (0.70) after adjusting for weight, height, level of physical activity, and BMD. These results suggest that the abnormalities of collagen may impact on bone mass measurements differently depending on skeletal site, modality of the assessment, and the source and nature of collagen defects. To determine whether collagen properties influence QUS, proper models in vivo and in vitro should be used.

Ultrasound measurements of the calcaneus: effects of ethnicity.

This study investigated whether there were differences in quantitative ultrasound (QUS) of the calcaneus between African-American and Caucasian females. QUS-1X, an ultrasonometer by Metra Biosystems Inc., was used to determine broadband ultrasound attenuation (UBI-4) using Burg Spectral Estimation in decibels/megahertz. The average transit time through the heel (TTH) in microseconds was used to estimate bone size. A multiple factor index taking into account bone size, UBI-4T, was calculated by dividing UBI-4 by TTH in decibels/(Megahertz x microseconds). Results showed that premenopausal Caucasian females (n = 37) have approx 6-8% lower values (p < 0.05) of QUS indices than their African-American (n = 54) counterparts. However, after adjusting for bone size, the differences in attenuation disappeared. Pilot data for males (Caucasian: n = 16, African-American: n = 18) suggest that the differences in QUS appear to be related to bone size. The limited scope of our study supports the fact that there are differences in QUS between premenopausal Caucasian and African-American females, but not with the same magnitude as evidenced by dual X-ray absorptiometry. We recommend that more data be collected on ethnic differences across all age ranges, to help understand how QUS may be used to assess bone mass and determine its value either as a screening tool to diagnose low bone mass or as a tool to predict osteoporotic fracture within various ethnic groups.

Plasma renin activity is associated with bone mineral density in premenopausal women.

Bone mineral density (BMD), plasma renin activity (PRA) and dietary calcium and sodium were evaluated in 47 Caucasian premenopausal women. All subjects were free of any disorder or medications known to affect calcium or bone metabolism. Those subjects with low PRA (< 1.3 ng/ml) had 4.3% lower BMD at the distal radius (p = 0.03). Other skeletal sites appeared to have lower BMD in subjects with low PRA but these differences were not statistically significant. There was a tendency for the low PRA group to have a lower dietary intake of calcium (p = 0.06) as compared with the normal PRA group (> or = 1.3 and < 4.0 ng/ml). Positive correlations were found between calcium intake and PRA (r = 0.26, p = 0.09); and between calcium/sodium intake and distal radial BMD (r = 0.31, p = 0.04), mid-radial BMD (r = 0.30, p = 0.04), total hip BMD (r = 0.23, p = 0.12) and total body BMD (r = 0.27, p = 0.07). This study provides preliminary evidence that a sodium intake > 3400 mg/day, as evidenced by the suppression of PRA, may affect bone mass and the effect may be modified by the level of calcium intake. Additional research is needed to replicate our findings with a larger sample size.

Low-fat diet practices of older women: prevalence and implications for dietary assessment.

OBJECTIVE: To evaluate the importance of information on low-fat diet practices and consumption of reduced-fat foods for accurate assessment of energy and fat intakes using a semiquantitative food frequency questionnaire (FFQ). SUBJECTS: Subjects were 7,419 women, aged 50 to 79 years, who filled out an FFQ as part of eligibility screening for a diet modification component and/or a hormone replacement trial in a multicenter study of chronic disease prevention in postmenopausal women (Women's Health Initiative). STATISTICAL ANALYSIS: For 26 FFQ questions, we recoded the low-fat diet choices of participants to a high-fat counterpart and recalculated energy and fat intakes. We then determined the decrease in energy and nutrient estimates attributable to adding low-fat options to the FFQ. RESULTS: Low-fat diet practices were widespread in this population. For example, 69% of respondents rarely or never ate skin on chicken, 76% rarely or never ate fat on meat, 36% usually drank nonfat milk, 52% usually ate low-fat or fat-free mayonnaise, 59% ate low-fat chips/snacks, and 42% ate nonfat cheese. These low-fat choices had substantial effects on energy and nutrient estimates. Absolute decreases (and mean percentage decreases) for energy and nutrient measures attributable to adding low-fat diet options to the FFQ were 196 kcal (11.4%) energy, 9 percentage points in percentage energy from fat (22.3%), 23.2 g fat (29.0%), and 9.6 g saturated fat (32.5%). Black and Hispanic women and women of lower socioeconomic status reported significantly fewer low-fat diet practices than white women and women of higher socioeconomic status. CONCLUSION: Failure to collect information on low-fat diet practices with an FFQ will result in an upward bias in estimates of energy and fat intake, and the amount of error will vary by the personal characteristics of respondents.

Misclassification of nutrient and energy intake from use of closed-ended questions in epidemiologic research.

The authors investigated the effect of collecting food frequency intake data using questionnaires that record response intervals rather than exact frequencies of consumption. Measures of energy and 24 nutrients were calculated using both types of frequency data for subjects' mean intakes, rank classifications and group mean values. Frequency data obtained between 1987 and 1989 using the open-ended Health Habits and History Questionnaire (HHHQ) developed by Block and associates at the National Cancer Institute were recoded into the interval response formats used by the computer-scannable version of the HHHQ and into the format used in the food frequency questionnaire developed by Willett for the Nurses' Health Study and other studies. Compared with the open-ended HHHQ, for otherwise identical data sets, the closed-ended HHHQ and Willett response categories produced significantly different (p < 0.05) measures of intake on the individual level for 18 (72%) (HHHQ) and 16 (64%) (Willett) of the 25 nutrient and energy measures studied, and they ranked 13-53% (HHHQ) and 16-52% (Willett) of subjects in different quintiles for the various measures. Use of food frequency questionnaires with closed-ended response categories causes nondifferential misclassification that could bias study results. To reduce such misclassification in epidemiologic studies, the authors recommend that food frequency questionnaires obtain exact frequencies of intake for measurement of diet exposure, and they describe an open-ended questionnaire layout which does so and also permits computer scanning of data.

Comparative changes in radial-bone density of elderly female lacto-ovovegetarians and omnivores.

A 5-y prospective study of the changes in radial-bone mineral density (BMD) of elderly white women (mean age, 81 y) living in four residential communities, including 49 Seventh-day Adventist lacto-ovovegetarians and 140 omnivores, was undertaken to determine the potential effects of usual dietary calcium in preventing the loss of BMD, measured by single-photon absorptiometry, at two radial sites. Changes in BMD and other variables from baseline (1983) to follow-up (1988) were: 1) mean calcium intakes in 1988 of 996 mg/d for omnivores and 733 mg/d for lacto-ovovegetarians changed little from 1983, 2) all women lost BMD (P < 0.05) over the 5 y period, 3) the annual BMD loss rates were approximately 1% at each site, 4) BMD loss was independent of calcium intake, 5) BMD loss rates were similar in both lacto-ovovegetarians and omnivores, and 6) the greater the loss of lean body mass, the greater the BMD loss (P < 0.05).