Faculty Bibliography

OBJECTIVE: Adults with serious psychological distress have a high likelihood of mental health problems severe enough to cause serious impairment in social and occupational functioning requiring treatment. These adults visit doctors frequently yet have poor health compared to adults without serious psychological distress. This study examined associations between emotional states of serious psychological distress in relationship to healthcare utilization indicators. A guiding hypothesis was that somatization underlying emotional states contributes to excessive healthcare seeking among adults with serious psychological distress. METHODS: Using 2006-2014 National Health Interview Survey, in adults with serious psychological distress (n=9271), the six states: unable to make efforts, nervousness, hopelessness, sadness, worthlessness and restlessness were assessed in multivariate models in relation to four healthcare utilization indicators: change in the usual place of healthcare, change due to insurance, having seen a healthcare provider in the last 6months and having 10 or more doctor visits in the last 12months. Models were adjusted for sociodemographic variables, having seen a mental health provider, and health conditions. RESULTS: Adults feeling unable to make efforts were more likely to seek healthcare in the last 6months and at least ten times in the last twelve months. Adults feeling hopeless were less likely to be heavy healthcare utilizers. CONCLUSIONS: Predisposing medical conditions do not fully explain healthcare utilization in adults with serious psychological distress. Educating healthcare providers about the emotional states motivating healthcare seeking, and integrating mental healthcare into primary care, may improve the health of adults with serious psychological distress.

Asian Americans have lower levels of physical activity (PA) compared to other racial/ethnic groups; however, there is little understanding of the social and cultural determinants of PA in this population. Few analyses describe specific PA domains (occupation-, transportation-, recreation-related), focus on one Asian subgroup, or use validated scales. The study objective was to assess the association between acculturation and activity behaviors (meeting 2008 PA guidelines, activity minutes by PA domain, sitting time) in a cross-sectional sample of urban-dwelling, Chinese American immigrants. Data were from the Chinese American Cardiovascular Health Assessment (CHA CHA) 2010-11 among participants with valid reports of PA minutes, assessed by the WHO Global Physical Activity Questionnaire (n = 1772). Acculturation was assessed using the Stephenson Multigroup Acculturation Scale, a 32-item instrument which characterizes two acculturative dimensions: ethnic society (Chinese) immersion and dominant society (American) immersion (maximum possible scores = 4). Multivariable models regressing activity behaviors on acculturation were run, adjusting for age, sex, household income, education, and age at immigration. Ethnic society immersion was high (mean = 3.64) while dominant society immersion was moderate (mean = 2.23). Higher ethnic society immersion was associated with less recreation-related PA (- 40.7 min/week); higher dominant society immersion was associated with a higher odds of meeting PA guidelines (OR: 1.66 (1.25, 2.20), p < 0.001) and more recreation-related PA (+ 36.5 min/week). Given low PA levels in Chinese adults in China, results suggest that PA for leisure may increase and become a more normative behavior among Chinese American immigrants with acculturation. Understanding acculturation level may inform strategies to increase PA in Chinese Americans.

OBJECTIVE: Studies suggest protein intake may be associated with lower body weight, but protein has also been associated with preservation of lean body mass. Understanding the role of protein in maintaining health for older adults is important for disease prevention among this population. DESIGN: Cross-sectional study of the relationship of dietary protein on body composition. SETTING: New York City community centers. PARTICIPANTS: 1,011 Black, White, and Latino urban men and women 60-99 years of age. MEASUREMENTS: Protein intake was assessed using two interviewer-administered 24-hour recalls, and body composition was assessed using bioelectrical impedance analysis (BIA) of fat mass (kg) (FM), fat free mass (kg) (FFM), and impedance resistance (Ohms). STATISTICAL ANALYSIS: Indices of FM and FFM were calculated by dividing BIA measurements by height squared (m2), and percent FFM was calculated by dividing FFM by the sum of FM and FFM. Log linear models adjusting for age (continuous), race/ethnicity, education, physical activity (dichotomized at the median), hypertension, diabetes, and total calories (continuous). RESULTS: Just 33% of women and 50% of men reported meeting the RDA for protein. Both fat free mass index (FFMI) and fat mass index (FMI) were negatively associated with meeting the RDA for protein (Women: FFMI -1.78 95%CI [-2.24, -1.33], FMI -4.12 95% CI [-4.82, -3.42]; Men: FFMI -1.62 95% CI [-2.32, -0.93] FMI -1.80 95% CI [-2.70, -0.89]). After accounting for confounders, women and men consuming at least 0.8 g/kg/day had a 6.2% (95% CI: 5.0%, 7.4%) and a 3.2% (95% CI 1.1%, 5.3%) higher percent fat free mass, respectively. CONCLUSIONS: FFM, FFMI, FM, and FMI were inversely related to meeting the RDA for protein. Meeting the RDA for protein of at least 0.8g/kg/day was associated with a higher percentage of fat free mass among older adults. These results suggest meeting the protein recommendations of at least 0.8 g/kg/day may help to promote lower overall body mass, primarily through loss of fat mass rather than lean mass.

Adiposity is an established risk factor for postmenopausal breast cancer. Recent data suggest that high insulin levels in overweight women may play a major role in this relationship, due to insulin's mitogenic/antiapoptotic activity. However, whether overweight women who are metabolically healthy (i.e., normal insulin sensitivity) have elevated risk of breast cancer is unknown. We investigated whether overweight women with normal insulin sensitivity [i.e., homeostasis model assessment of insulin resistance (HOMA-IR) index, or fasting insulin level, within the lowest quartile (q1)] have increased breast cancer risk. Subjects were incident breast cancer cases (N = 497) and a subcohort (N = 2,830) of Women's Health Initiative (WHI) participants with available fasting insulin and glucose levels. In multivariate Cox models, metabolically healthy overweight women, defined using HOMA-IR, were not at elevated risk of breast cancer compared with metabolically healthy normal weight women [HRHOMA-IR, 0.96; 95% confidence interval (CI), 0.64-1.42]. In contrast, the risk among women with high (q3-4) HOMA-IRs was elevated whether they were overweight (HRHOMA-IR, 1.76; 95% CI, 1.19-2.60) or normal weight (HRHOMA-IR, 1.80; 95% CI, 0.88-3.70). Similarly, using fasting insulin to define metabolic health, metabolically unhealthy women (insulin q3-4) were at higher risk of breast cancer regardless of whether they were normal weight (HRinsulin, 2.06; 95% CI, 1.01-4.22) or overweight (HRinsulin, 2.01; 95% CI, 1.35-2.99), whereas metabolically healthy overweight women did not have significantly increased risk of breast cancer (HRinsulin, 0.96; 95% CI, 0.64-1.42) relative to metabolically healthy normal weight women. Metabolic health (e.g., HOMA-IR or fasting insulin) may be more biologically relevant and more useful for breast cancer risk stratification than adiposity per se.

OBJECTIVE: Observational studies highlight a possible relationship between sodium intake and obesity. This investigation explores the cross-sectional relationships between sodium intake and measures of body size and fatness (body mass index [BMI], weight, waist circumference, predictive body fatness). METHODS: Analyses were performed using data from participants in the National Health and Nutrition Examination Survey (NHANES) 2009-10 with two 24-h dietary recalls and measures of body size and fatness (n = 4,613). Regression analyses assessed the relationships of sodium (1,000 mg/day) with outcomes, adjusting for caloric intake. Analyses are presented overall and by sex; data were weighted to be representative of the non-institutionalized US adult population. RESULTS: Positive associations between sodium intake and measures of body size and predictive body fatness were observed, and the magnitude of association was larger in women than in men. For each 1,000 mg/day higher sodium intake, BMI was 1.03 kg/m2 higher; weight was 2.75 kg higher; waist circumference was 2.15 cm higher; and predictive body fatness was 1.18% higher after adjustment for energy intake. CONCLUSIONS: Longitudinal analyses examining associations between sodium intake and measures of body size and body fatness are needed.

BACKGROUND: Measurement error in self-reported sugars intake may be obscuring the association between sugars and cancer risk in nutritional epidemiologic studies. METHODS: We used 24-hour urinary sucrose and fructose as a predictive biomarker for total sugars, to assess measurement error in self-reported sugars intake. The Nutrition and Physical Activity Assessment Study (NPAAS) is a biomarker study within the Women's Health Initiative (WHI) Observational Study that includes 450 postmenopausal women ages 60 to 91 years. Food Frequency Questionnaires (FFQ), four-day food records (4DFR), and three 24-hour dietary recalls (24HRs) were collected along with sugars and energy dietary biomarkers. RESULTS: Using the biomarker, we found self-reported sugars to be substantially and roughly equally misreported across the FFQ, 4DFR, and 24HR. All instruments were associated with considerable intake- and person-specific bias. Three 24HRs would provide the least attenuated risk estimate for sugars (attenuation factor, AF = 0.57), followed by FFQ (AF = 0.48) and 4DFR (AF = 0.32), in studies of energy-adjusted sugars and disease risk. In calibration models, self-reports explained little variation in true intake (5%-6% for absolute sugars and 7%-18% for sugars density). Adding participants' characteristics somewhat improved the percentage variation explained (16%-18% for absolute sugars and 29%-40% for sugars density). CONCLUSIONS: None of the self-report instruments provided a good estimate of sugars intake, although overall 24HRs seemed to perform the best. IMPACT: Assuming the calibrated sugars biomarker is unbiased, this analysis suggests that measuring the biomarker in a subsample of the study population for calibration purposes may be necessary for obtaining unbiased risk estimates in cancer association studies.

OBJECTIVE: Circulating free insulin-like growth factor (IGF)-I and its binding proteins, most notably, IGFBP-1 and IGFBP-2, have been prospectively associated with incident type 2 diabetes in women. However, little is known regarding the factors that may influence these IGF-axis protein levels. The aim is to study the relation of IGF-axis protein levels with adipcytokines, macronutrient consumption, and other factors related to diabetes. DESIGN: Fasting plasma from 558 controls enrolled in a nested case-control study within the Nurses' Health Study of incident type 2 diabetes in women was tested for: IGF-axis proteins (free and total IGF-I, IGFBP-1, IGFBP-2, IGFBP-3), adipocytokines (leptin, adiponectin, resistin), soluble leptin receptor (sOB-R), inflammatory factors (IL-18 and C-reactive protein (CRP)), insulin, and glycated hemoglobin (HbA1C). RESULTS: In multivariate models, each 1% increase in sOB-R (mean 34.9ng/mL, standard deviation (SD) +/-11.3) was associated with -0.20% total IGF-I (P=0.0003) and -0.42% free IGF-I (P=0.002), as well as 0.73% higher IGFBP-1 (P<0.0001) and 0.27% IGFBP-2 (P=0.003). For example, a one SD change from the mean sOB-R level was associated with 11% lower free IGF-I. Insulin levels (mean 6.8muU/mL+/-5.3) were inversely and adiponectin (mean 18.3mug/mL+/-7.4) positively associated with IGFBP-1 and IGFBP-2 (all P<0.01). Consumption of dairy protein, monounsaturated fats, and saturated fats, was also correlated with IGF-axis protein levels (all P<0.05). CONCLUSIONS: Several molecular factors and macronutrients were independently associated with plasma IGF-axis protein levels. Which of these, if any, reflect biologic relationships that can be intervened upon to influence IGF-axis protein concentrations warrants further investigation.

OBJECTIVE: With aging, kidney function declines, as evidenced by reduced glomerular filtration rate. It is controversial whether or not high protein intake accelerates this decline. The aim of this study was to determine whether high protein intake was associated with declines in kidney function among older patients. METHODS: We examined whether dietary protein is associated with change in kidney function (mean follow-up 6.4 y [SD = 1.4, range = 2.5-7.9] in the Cardiovascular Health Study (N = 3623). We estimated protein intake using a food frequency questionnaire and estimated glomerular filtration rate from cystatin C. Associations between protein intake and kidney function were determined by linear and logistic regression models. RESULTS: Average protein intake was 19% of energy intake (SD = 5%). Twenty-seven percent (n = 963) of study participants had rapid decline in kidney function, as defined by (DeltaeGFRcysC > 3 mL*min*1.73 m(2)). Protein intake (characterized as g/d and % energy/d), was not associated with change in estimated glomerular filtration rate (P > 0.05 for all comparisons). There were also no significant associations when protein intake was separated by source (animal and vegetable). CONCLUSION: These data suggest that higher protein intake does not have a major effect on kidney function decline among elderly men and women.

BACKGROUND: The effects of dietary protein on bone health are controversial. OBJECTIVE: We examined the relation between protein intake with fracture and bone mineral density (BMD) within the Women's Health Initiative (WHI). DESIGN: This prospective analysis included 144,580 women aged 50-79 y at baseline in the WHI clinical trials (CTs) and observational study (OS) that recruited participants in 1993-1998 with follow-up through 2011. Self-reported clinical fractures were collected semiannually through the original end of the trials (WHI CTs) and annually (WHI OS) by questionnaires. Hip fracture was adjudicated by a central review of radiology reports. BMDs for total body, hip, and spine were measured at baseline and 3 and 6 y in 9062 women at 3 WHI clinics by using dual-energy X-ray absorptiometry. Protein intake was assessed via food-frequency questionnaire and calibrated by using biomarkers of energy and protein intakes. Associations between protein intake and fracture were estimated by using Cox proportional hazards regression, and the relation between protein intake and BMD was estimated by using linear regression. RESULTS: Median biomarker-calibrated protein intake was 15% of energy intake. Per 20% increase in calibrated protein intake (percentage of energy), there was no significant association with total fracture (HR: 0.99; 95% CI: 0.97, 1.02) or hip fracture (HR: 0.91; 95% CI: 0.84, 1.00), but there was an inverse association with forearm fracture (HR: 0.93; 95% CI: 0.88, 0.98). Each 20% increase in calibrated protein intake was associated with a significantly higher BMD for total body (mean 3-y change: 0.003 g/cm(2); 95% CI: 0.001, 0.005 g/cm(2)) and hip (mean 3-y change: 0.002 g/cm(2); 95% CI: 0.001, 0.004 g/cm(2)). CONCLUSIONS: Higher biomarker-calibrated protein intake within the range of usual intake was inversely associated with forearm fracture and was associated with better maintenance of total and hip BMDs. These data suggest higher protein intake is not detrimental to bone health in postmenopausal women.