Comparison of body composition by bioelectrical impedance analysis and dual-energy X-ray absorptiometry in Hispanic diabetics.

OBJECTIVE: The purpose of this study was to compare Tanita tetrapolar foot-to-foot bioelectrical impedance analysis (Model TBF-310, Tanita Corporation of America, Inc, Arlington Heights, IL; Tanita-BIA) and fan beam dual-energy X-ray absorptiometry (Hologic Discovery A v12.6, Waltham, MA; DXA) in diabetic patients. METHODS: Seventy Hispanic diabetic participants (23 male, 47 female; mean age: 53.03 ± 10.32 yrs; mean weight: 81.45 ± 17.65 kg; and mean body mass index: 31.40 ± 6.80 kg/m(2)) were selected from the Loma Linda University En Balance culturally-sensitive Spanish diabetes education program using the baseline data. RESULTS: DXA vs Tanita-BIA fat mass (FM), percent fat mass (%FM), and fat-free mass (FFM) were compared using Pearson's (FM: 0.96, %FM: 0.91, and FFM: 0.95), and Spearman's rank (FM: 0.94, %FM: 0.91, and FFM: 0.93) correlation coefficients. Bland-Altman analyses were also used to compare the difference (DXA - BIA) vs average of DXA and BIA results and showed general agreement between the two methods. When Tanita-BIA was regressed onto DXA, the adjusted R(2) was: FM=0.91; %FM=0.83; FFM=0.90. Gender combined concordance correlations with 95% confidence intervals were calculated using a bootstrap re-sampling of the data and found high associations [FM: 0.93 (95% CI: 0.89, 0.96)], [%FM: 0.86 (95% CI: 0.79, 0.90)], and [FFM: 0.93 (95% CI: 0.89, 0.96)]. CONCLUSION: Tanita-BIA may provide valid measures of fat, percent body fat and fat-free mass in Hispanic diabetics, and could be a convenient and practical approach for assessment in community-based research.

Comparing biological measurements of vitamin C, folate, alpha-tocopherol and carotene with 24-hour dietary recall information in nonhispanic blacks and whites.

PURPOSE: To assess intake of several vitamins in preparation for a large cohort study investigating the effect of diet on risk of colon and prostate cancer. METHODS: The dietary intake of several vitamins were assessed using eight different 24-hour recalls and a 200-item food frequency questionnaire (FFQ) from each subject. Participants also attended a clinic where blood was drawn and body composition, weight, height, and blood pressure were measured. A total of 97 black and 96 nonhispanic white subjects participated. The levels of alpha-tocopherol, carotene, folate, and vitamin C in the blood were correlated with the dietary intakes as measured by both 24-hour recalls and FFQ. RESULTS: Correlations between blood levels and energy-adjusted dietary intake assessed by 24-hour recalls (with supplements) were as follows: carotene (adjusted for serum cholesterol): 0.47 and 0.55 in black and white subjects, respectively; alpha-tocopherol (adjusted for serum cholesterol): 0.61 (blacks) and 0.50 (whites); vitamin C: 0.22 (blacks) and 0.17 (whites); folate: 0.54 (blacks) and 0.55 (whites). Correlations between blood levels and FFQ indices were smaller in magnitude: 0.34 and 0.28 for carotene in black and white subjects, respectively, 0.37 and 0.56 for alpha-tocopherol (adjusted for serum cholesterol), 0.20 and 0.03 for vitamin C and 0.24 and 0.32 for folate. CONCLUSIONS: The correlations observed were generally of modest to moderate size and were similar to or larger than those reported by others. This is despite variations in absorption, metabolism, and excretion of the vitamins and suggests that both the 24-hour recalls and the FFQ contain valid information.

Types of dietary fat and breast cancer: a pooled analysis of cohort studies.

Recently, there has been interest in whether intakes of specific types of fat are associated with breast cancer risk independently of other types of fat, but results have been inconsistent. We identified 8 prospective studies that met predefined criteria and analyzed their primary data using a standardized approach. Holding total energy intake constant, we calculated relative risks for increments of 5% of energy for each type of fat compared with an equivalent amount of energy from carbohydrates or from other types of fat. We combined study-specific relative risks using a random effects model. In the pooled database, 7,329 incident invasive breast cancer cases occurred among 351,821 women. The pooled relative risks (95% confidence intervals [CI]) for an increment of 5% of energy were 1.09 (1.00-1.19) for saturated, 0.93 (0.84-1.03) for monounsaturated and 1.05 (0.96-1.16) for polyunsaturated fat compared with equivalent energy intake from carbohydrates. For a 5% of energy increment, the relative risks were 1.18 (95% CI 0.99-1.42) for substituting saturated for monounsaturated fat, 0.98 (95% CI 0.85-1.12) for substituting saturated for polyunsaturated fat and 0.87 (95% CI 0.73-1.02) for substituting monounsaturated for polyunsaturated fat. No associations were observed for animal or vegetable fat intakes. These associations were not modified by menopausal status. These data are suggestive of only a weak positive association with substitution of saturated fat for carbohydrate consumption; none of the other types of fat examined was significantly associated with breast cancer risk relative to an equivalent reduction in carbohydrate consumption.

Intake of fruits and vegetables and risk of breast cancer: a pooled analysis of cohort studies.

CONTEXT: Some epidemiologic studies suggest that elevated fruit and vegetable consumption is associated with a reduced risk of breast cancer. However, most have been case-control studies in which recall and selection bias may influence the results. Additionally, publication bias may have influenced the literature on associations for specific fruit and vegetable subgroups. OBJECTIVE: To examine the association between breast cancer and total and specific fruit and vegetable group intakes using standardized exposure definitions. DATA SOURCES/STUDY SELECTION: Eight prospective studies that had at least 200 incident breast cancer cases, assessed usual dietary intake, and completed a validation study of the diet assessment method or a closely related instrument were included in these analyses. DATA EXTRACTION: Using the primary data from each of the studies, we calculated study-specific relative risks (RRs) that were combined using a random-effects model. DATA SYNTHESIS: The studies included 7377 incident invasive breast cancer cases occurring among 351 825 women whose diet was analyzed at baseline. For comparisons of the highest vs lowest quartiles of intake, weak, nonsignificant associations were observed for total fruits (pooled multivariate RR, 0.93; 95% confidence interval [CI], 0.86-1.00; P for trend =.08), total vegetables (RR, 0.96; 95% CI, 0.89-1.04; P for trend =.54), and total fruits and vegetables (RR, 0.93; 95% CI, 0.86-1.00; P for trend =.12). No additional benefit was apparent in comparisons of the highest and lowest deciles of intake. No associations were observed for green leafy vegetables, 8 botanical groups, and 17 specific fruits and vegetables. CONCLUSION: These results suggest that fruit and vegetable consumption during adulthood is not significantly associated with reduced breast cancer risk.

Late rejection is a predictor of transplant coronary artery disease in children.

OBJECTIVE: The study objectives were to determine posttransplant coronary artery disease (TxCAD) incidence, predisposing factors and optimal timing for retransplantation (re-Tx) in pediatric heart transplantation (Tx) recipients. BACKGROUND: The TxCAD limits long-term survival following heart Tx, with re-Tx being the primary therapy. Information on risk factors and timing of listing for re-Tx is limited in children. METHODS: The records of children who survived >1 year post-Tx at Loma Linda University were reviewed. Nonimmune and immune risk factors were analyzed. RESULTS: TxCAD was documented in 24 of 210 children. Freedom from TxCAD was 92 +/- 2% and 75 +/- 5% at 5 and 10 years' post-Tx, respectively. The TxCAD diagnosis was established at autopsy in 10 asymptomatic patients who died suddenly within nine months following the most recent negative angiograms. The remaining 14 children had angiographic diagnoses of TxCAD and had symptoms and/or graft dysfunction (n = 10) or positive stress studies (n = 4). Three of 14 died within three months after the diagnosis was made. Eleven patients underwent re-Tx within seven months of diagnosis; nine survived. Univariate and multivariate analyses showed that only late rejection (>1 year posttransplant) frequency (p = 0.025) and severity (hemodynamically compromising) (p < 0.01) were independent predictors of TxCAD development. Freedom from TxCAD after severe late rejection was 78 +/- 8% one year postevent and 55 +/- 10% by two years. CONCLUSIONS: Late rejection is an independent predictor of TxCAD. Patients suffering severe late rejection develop angiographically apparent TxCAD rapidly and must be monitored aggressively. Both TxCAD mortality and morbidity occur early; therefore, we recommend immediate listing for re-Tx upon diagnosis.

Long-term concentrations of ambient air pollutants and incident lung cancer in California adults: results from the AHSMOG study.Adventist Health Study on Smog.

The purpose of this study was to evaluate the relationship of long-term concentrations of ambient air pollutants and risk of incident lung cancer in nonsmoking California adults. A cohort study of 6,338 nonsmoking, non-Hispanic, white Californian adults, ages 27-95, was followed from 1977 to 1992 for newly diagnosed cancers. Monthly ambient air pollution data were interpolated to zip code centroids according to home and work location histories, cumulated, and then averaged over time. The increased relative risk (RR) of incident lung cancer in males associated with an interquartile range (IQR) increase in 100 ppb ozone (O3) was 3.56 [95% confidence interval (CI), 1.35-9.42]. Incident lung cancer in males was also positively associated with IQR increases for mean concentrations of particulate matter <10 microm (PM10; RR = 5.21; CI, 1.94-13.99) and SO2 (RR = 2.66; CI, 1.62-4.39). For females, incident lung cancer was positively associated with IQR increases for SO2 (RR = 2.14; CI, 1.36-3.37) and IQR increases for PM10 exceedance frequencies of 50 microg/m3 (RR = 1.21; CI, 0.55-2.66) and 60 microg/m3 (RR = 1.25; CI, 0.57-2.71). Increased risks of incident lung cancer were associated with elevated long-term ambient concentrations of PM10 and SO2 in both genders and with O3 in males. The gender differences for the O3 and PM10 results appeared to be partially due to gender differences in exposure.

Validity of dietary recall over 20 years among California Seventh-day Adventists.

Past dietary habits are etiologically important to incident disease. Yet the validity of such measurements from the previous 10-20 years is poorly understood. In this study, the authors correlated food frequency results that were obtained in 1994-1995 but pertained to recalled diet in 1974 with the weighted mean of five random 24-hour dietary recalls obtained by telephone in 1974. The subjects studied were 72 Seventh-day Adventists who lived within 30 miles of Loma Linda, California; had participated in a 1974 validation study; were still alive; and were willing to participate again in 1994. A method was developed to allow correction for random error in the reference data when these data had differentially weighted components. The results showed partially corrected correlation coefficients of greater than 0.30 for coffee, whole milk, eggs, chips, beef, fish, chicken, fruit, and legumes. Higher correlations on average were obtained when the food frequencies were scored simply 1-9, reflecting the nine frequency categories. The 95% confidence intervals for 15 of the 28 correlations excluded zero. Incorporation of portion size information was unhelpful. The authors concluded that in this population, data recalled from 20 years ago should be treated with caution but, for a number of important foods, that the degree of validity achieved approached that obtained when assessing current dietary habits.

Healthy volunteer effect in a cohort study: temporal resolution in the Adventist Health Study.

The healthy volunteer effect was studied by comparing 6 years of mortality data for 31,124 participants from the Adventist Health Study (AHS) who responded to both a relatively brief census questionnaire (CQ) in 1974 and a detailed life-style questionnaire (LQ) in 1976 (responders), to mortality data for 8,762 individuals who did not respond to the second questionnaire. The rate ratio (RR) comparing LQ nonresponders to responders for all cause mortality decreased from 2.5 (2.2-2.9) in 1977 to 1.4 (1.2-1.7) in 1982 (p for trend = 0.02); for ischemic heart disease mortality from 2.3 (1.8-3.0) to 1.3 (1.0-1.7); and for all sites cancer mortality from 1.8 (1.3-2.5) to 1.5 (1.1-2.0). The death rate decreased markedly among nonresponders and increased slightly among responders during the study. Similar results were seen for age and gender subgroups. Multivariate analysis controlling for confounding variables confirms these results, except that the apparent effect of education is probably due to effect modification by age. The RR decreased to about one after 3 years of follow-up in young subjects but remained elevated (> 2) in older subjects. Available sociodemographic information reveals that a higher proportion of responders are married, have college education, are SDA church members, and use medical services less than nonresponders during the previous year. Because the risk remains elevated at the end of the study in some but not all subgroups, it seems reasonable that the elevated risk in nonresponders may be due in part to a less healthy life style and in part to exclusion of individuals who did not feel well during enrollment. The results suggest that for internal comparisons no bias is likely to occur; but descriptive statistics for certain subgroup comparisons, and external comparisons, may be biased by the healthy volunteer effect.

Ventricular remodeling following infant-pediatric cardiac transplantation. Does age at transplantation or size disparity matter?

Early left ventricular (LV) remodeling following pediatric cardiac transplantation has not been described. To identify patterns and determinants of change in left ventricular mass and volume posttransplant, we studied 125 consecutive children who underwent cardiac transplantation between January 1, 1989 and July 31, 1993. Two-dimensional imaging-directed M-mode echocardiograms were studied weekly until 26 weeks post-transplant. LV mass and volume (indexed to BSA1.5) were measured. LV mass index increased until 3 weeks post-transplant, and then decreased. The mean decrement in LV mass index after 8 weeks post-transplant (relative to baseline) was significantly larger in patients with donor-recipient weight ratio > 1.5 compared with patients with donor-recipient weight ratio < or = 1.5 (-2.2 g/m3 compared with 33.4 g/m3, respectively, P < 0.01). Multiple linear regression was performed employing donor-recipient weight ratio, time since transplantation, ischemic time, and age at transplant as prognostic variables. Donor-recipient weight ratio (P < 0.0001), time since transplant (P < 0.01), and age at transplant (P = 0.02) were identified as independent predictors of change in LV mass index. Donor-recipient weight ratio (P = 0.001) and time since transplantation (P = 0.02) were independent predictors of change in LV volume index. There was an interaction between donor-recipient weight ratio and time since transplantation, suggesting that donor-recipient weight ratio has an independent effect as well as a time-dependent effect on change in LV mass and volume indices. LV mass and volume indices increased early posttransplant and then decreased; this pattern was temporally predictable, and dependent on donor-recipient weight ratio and age at transplant.

Effect of risk factor values on lifetime risk of and age at first coronary event. The Adventist Health Study.

The effect of traditional coronary heart disease risk factors on lifetime risk, age at onset, and survival free of coronary disease has not been extensively studied. The authors have used the cohort data from 27,321 California Seventh-day Adventists who had no known heart disease in 1976 to investigate these questions. Multiple decrement life tables incorporating non-parametric estimates of conditional probabilities for both coronary disease and all other competing endpoints were used to estimate these survival outcomes. Variance estimators are provided in an appendix. Persons characterized by being either past smokers, diabetic, hypertensive, physically, non-vegetarian, or infrequent consumers of nuts often showed substantial differences in these survival outcomes. Statistically significant results include earlier age at onset of coronary disease at between 4 and 10 years, reduced life expectancy free of the disease between 5 and 9 years, and increased lifetime risk between 8% and 16%, when comparing groups with and without adverse values for different risk factors. The presence of adverse levels of two risk factors predicted even greater differences in these endpoints. These important effects are easily understood by the layman or non-epidemiologist professional, which is often not true of a relative risk. This should increase the effectiveness of such results when promoting behavioral change.

Cancer incidence among California Seventh-Day Adventists, 1976-1982.

Cancer incidence was monitored in a population of 34,000 Seventh-day Adventists in California. By religious belief, Adventists do not consume tobacco, alcohol, or pork and approximately one-half adhere to a lacto-ovovegetarian lifestyle. Only a small percentage are pure vegetarians. Comparisons of cancer-incidence rates in this population with an external reference population were completed by calculating standardized morbidity ratios (SMRs) for all cancer sites. Also, within the population, relative risks were calculated by using data obtained from a detailed lifestyle questionnaire that members of the study population completed. For all cancer sites combined in males, the SMR was lower in the Adventists (SMR = 0.73). The SMR was also lower in males for most individual cancer sites. However, prostate cancer risk was higher. For females, the all-cancer SMR was lower but not significantly so (SMR = 92). Most site-specific SMRs were lower, although not as much as the male SMRs. The SMR for endometrial cancer was significantly higher in female Adventists.

Chronic disease associated with long-term concentrations of nitrogen dioxide.

A prospective epidemiologic cohort study of 6,000 residentially stable and non-smoking Seventh-day Adventists (SDA) in California was conducted to evaluate long-term cumulative levels of ambient nitrogen dioxide (NO2) in association with several chronic diseases. These diseases included respiratory symptoms, cancer, myocardial infarction (MI), and all natural causes mortality. Cumulative ambient concentrations of NO2 were estimated for each study subject using monthly interpolations from fixed site monitoring stations and applying these estimates to the monthly residence and work place zip code histories of study participants. In addition, a personal NO2 exposure study on a randomly selected sample of 650 people in southern California was conducted to predict total personal NO2 exposure using household and lifestyle characteristics and ambient NO2 concentrations. It was found that good predictability could be obtained (correlation coefficient between predicted and observed values = 0.79) from a model predicting personal NO2. The resulting regression equations from the personal NO2 exposure study were applied to the epidemiologic study cohort to adjust ambient concentrations of NO2.

Long-term ambient concentrations of total suspended particulates, ozone, and sulfur dioxide and respiratory symptoms in a nonsmoking population.

Seventh-day Adventist nonsmokers, who, subsequent to 1966, had resided within 8 km (5 miles) of their 1977 residence (N = 3,914), completed the National Heart and Lung Institute (NHLI) respiratory symptoms questionnaire in 1977 and again in 1987. For each participant, cumulative ambient concentrations of total suspended particulates (TSP), ozone, and sulfur dioxide (SO2) in excess of several cutoff levels were estimated by month and by interpolating ambient concentrations from state air-monitoring stations to their residential and workplace zip codes for the month. Statistically significant relationships between ambient concentrations of TSP and ozone, but not SO2, were found with several respiratory disease outcomes. Multivariate analyses adjusted for past and passive smoking and occupational exposures. Results are discussed within the context of standards setting for TSP and ozone.

The incidence of dementia and intake of animal products: preliminary findings from the Adventist Health Study.

We investigated the relationship between animal product consumption and evidence of dementia in two cohort substudies. The first enrolled 272 California residents matched for age, sex, and zip code (1 vegan, 1 lacto-ovo-vegetarian, and 2 'heavy' meat eaters in each of 68 quartets). This design ensured a wide range of dietary exposure. The second included 2,984 unmatched subjects who resided within the Loma Linda, California area. All subjects were enrolled in the Adventist Health Study. The matched subjects who ate meat (including poultry and fish) were more than twice as likely to become demented as their vegetarian counterparts (relative risk 2.18, p = 0.065) and the discrepancy was further widened (relative risk 2.99, p = 0.048) when past meat consumption was taken into account. There was no significant difference in the incidence of dementia in the vegetarian versus meat-eating unmatched subjects. There was no obvious explanation for the difference between the two substudies, although the power of the unmatched sub-study to detect an effect of 'heavy' meat consumption was unexpectedly limited. There was a trend towards delayed onset of dementia in vegetarians in both substudies.

Allergy and cancer: organ site-specific results from the Adventist Health Study.

The relation between allergy and risk of cancer was evaluated in a cohort study of 34,198 Seventh-day Adventists in California. Information on prevalence of asthma, hay fever, and reactions to chemicals, medications, bee stings, and poison oak (or ivy) was obtained by questionnaire in 1976. The reported allergies must have been serious enough to require treatment by a physician. The cohort was then followed for 6 years (1977-1982). Both stratified analysis and Cox proportional hazards regression analyses were utilized to evaluate the relation of allergy to cancer after taking into account several potentially confounding variables. For all cancer sites combined in males, there was a 33% increased risk associated with reaction to medications. In contrast, among females, reaction to medications was associated with a 21% decrease in risk. Both results were statistically significant. Prostate and breast cancer risk were elevated in persons who reported any type of allergic history, as was risk of lymphatic or hematopoietic cancers and sarcoma. For each of these types of cancer, risk increased with increasing numbers of allergies. However, ovarian cancer risk was decreased in persons with any allergic history and increasing numbers of allergies was associated with decreasing risk of this form of cancer. These results suggest that the association between allergy and cancer is complex and depends on the specific allergy and the specific organ site under consideration.

Effects of traditional coronary risk factors on rates of incident coronary events in a low-risk population. The Adventist Health Study.

BACKGROUND: California Seventh-Day Adventists have lower mortality rates from coronary heart disease (CHD) than other Californians. Associations between traditional risk factor and CHD events have not been reported previously for Adventists. METHODS AND RESULTS: A cohort study allowed 6 years of follow-up of 27,658 male and female California Seventh-Day Adventists. Data collected included age, sex, physician-diagnosed hypertension and diabetes mellitus, body height, weight, previous and current cigarette smoking habits, and current exercise habits. Incident cases of definite myocardial infarction (MI) and definite fatal CHD were diagnosed according to recognized criteria. Both stratified and proportional hazards analyses demonstrated that in this low-risk population, the above traditional coronary risk factors exhibit their usual associations with risk of CHD events. It was noted that exercise had a strong negative association with fatal CHD events (relative risks [RR], 1.0, 0.66, and 0.50 with increasing exercise) but no association with risk of MI (either nonfatal or all cases). Conversely, obesity was much more clearly associated with MI (RR, 1.0, 1.18, and 1.83 with increasing tertiles of obesity) than with fatal events. The importance of the risk factors was similar in both sexes, except that the effect of cigarette smoking seemed more pronounced in women. CONCLUSIONS: The epidemiology of coronary heart disease in this low-risk California population appears to be at least qualitatively similar to that seen in other groups. There was evidence that the effects of exercise and obesity may differ depending on whether fatal CHD and MI (either all MI or nonfatal alone) is the end point.

A possible protective effect of nut consumption on risk of coronary heart disease. The Adventist Health Study.

BACKGROUND: Although dietary factors are suspected to be important determinants of coronary heart disease (CHD) risk, the direct evidence is relatively sparse. METHODS: The Adventist Health Study is a prospective cohort investigation of 31,208 non-Hispanic white California Seventh-Day Adventists. Extensive dietary information was obtained at baseline, along with the values of traditional coronary risk factors. These were related to risk of definite fatal CHD or definite nonfatal myocardial infarction. RESULTS: Subjects who consumed nuts frequently (more than four times per week) experienced substantially fewer definite fatal CHD events (relative risk, 0.52; 95% confidence interval [CI], 0.36 to 0.76) and definite nonfatal myocardial infarctions (relative risk, 0.49; 95% CI, 0.28 to 0.85), when compared with those who consumed nuts less than once per week. These findings persisted on covariate adjustment and were seen in almost all of 16 different subgroups of the population. Subjects who usually consumed whole wheat bread also experienced lower rates of definite nonfatal myocardial infarction (relative risk, 0.56; 95% CI, 0.35 to 0.89) and definite fatal CHD (relative risk, 0.89; 95% CI, 0.60 to 1.33) when compared with those who usually ate white bread. Men who ate beef at least three times each week had a higher risk of definite fatal CHD (relative risk, 2.31; 95% CI, 1.11 to 4.78), but this effect was not seen in women or for the nonfatal myocardial infarction end point. CONCLUSION: Our data strongly suggest that the frequent consumption of nuts may protect against risk of CHD events. The favorable fatty acid profile of many nuts is one possible explanation for such an effect.

Ambient air pollution and cancer in California Seventh-day Adventists.

Cancer incidence and mortality in a cohort of 6,000 Seventh-day Adventist nonsmokers who were residents of California were monitored for a 6-y period, and relationships with long-term ambient concentrations of total suspended particulates (TSPs) and ozone (O3) were studied. Ambient concentrations were expressed as mean concentrations and exceedance frequencies, which are the number of hours during which concentrations exceeded specified cutoffs (e.g., federal and California air quality standards). Risk of malignant neoplasms in females increased concurrently with exceedance frequencies for all TSP cutoffs, except the lowest, and these increased risks were highly statistically significant. An increased risk of respiratory cancers was associated with only one cutoff of O3, and this result was of borderline significance. These results are presented in the context of setting standards for these two air pollutants.