Nutritional, inflammatory, and ecological correlates of maternal retinol allocation to breast milk in agro-pastoral Ariaal communities of northern Kenya.

OBJECTIVES: Vitamin A (VA) is an essential micronutrient required for a range of biological functions throughout life. VA deficiency (VAD) claims an estimated 1 million preschool children's lives annually. Human milk is enriched with VA (retinol) from the maternal blood, which originates from the hepatic reserve and dietary intake. Secreting retinol into milk will benefit the nursing infant through breast milk, but retaining retinol is also important for the maternal health. Previous studies found that the public health intervention of high-dose VA supplementation to lactating mothers did not significantly lower child mortality. The World Health Organization (WHO) recently acknowledged that our understanding about the principle of VA allocation within the maternal system and the secretion into milk is too incomplete to devise an effective intervention. METHODS: We present a secondary analysis of data collected among lactating mothers in VAD endemic northern Kenya (n = 171), examining nutritional, inflammatory, and ecological factors that might associate with maternal retinol allocation. Regression models were applied using the outcome milk-retinol allocation index: milk retinol/(milk retinol + serum retinol). RESULTS: Ten percent of the sample was identified as VAD. The average milk retinol concentration was 0.1 µmo/L, grossly below what is considered minimally necessary for an infant (1 µmol/L). VAD mothers and mothers with inflammation did not seem to compromise their milk retinol even though their serum retinol was lower than non-VAD and noninflammation mothers. Breast milk fat concentration positively correlated with milk retinol but not with serum retinol. CONCLUSIONS: This exploratory study contributes toward an understanding of maternal retinol allocation.

Comparison of the adherence to the american diabetes association guidelines of diabetes care in primary care and subspecialty clinics.

BACKGROUND: Diabetes mellitus is a major public health problem with significant morbidity and mortality. Evidence based guidelines have been proposed to reduce the micro and macrovascular complications, but studies have shown that these goals are not being met. We sought to compare the adherence to the American Diabetes Association guidelines for measurement and control of glycohemoglobin (A1c), blood pressure (BP), lipids (LDL) and microalbuminuria (MA) by subspecialty and primary care clinics in an academic medical center. METHODS: 390 random charts of patients with diabetes from Family Practice (FP), Internal Medicine (IM) and Diabetes (DM) clinics at Michigan State University were reviewed. RESULTS: We reviewed 131, 134 and 125 charts from the FP, IM and DM clinics, respectively. DM clinic had a higher percentage of patients with type 1 diabetes 43/125 (34.4%) compared with 7/131 (5.3%) in FP and 7/134 (5.2%) in IM clinics. A1c was measured in 99%, 97.8% and 100% subjects in FP, IM and DM clinics respectively. B.P. was measured in all subjects in all three clinics. Lipids were checked in 97.7%, 95.5% and 92% patients in FP, IM and DM clinics respectively. MA was measured at least once during the year preceding the office visit in 85.5%, 82.8% and 76.8% patients in FP, IM and DM clinics respectively. A1C was controlled (<7%) in 38.9, 43.3, 28.8% of patients in the FP, IM and DM clinics, respectively (p = 0.034). LDL was controlled (<100 mg/dl or 2.586 mmol/l) in 71.8, 64.9, 64% of patients in the FP, IM and DM clinics, respectively. MA was controlled (<30 mg/gm creatinine) in 60.3%, 51.5% and 60% patients in FP, IM and DM clinics respectively (P = 0.032). BP was controlled (<130/80) in 59.5, 67.2 and 52.8% patients in the FP, IM and DM clinics, respectively. CONCLUSION: Testing rates for A1C, LDL, and MA were high, in both subspecialty and primary care clinics. However, the degree of control was not optimal. Significantly fewer patients in the DM clinic had A1c <7%, the cause of which may be multifactorial.

Nutrient intakes associated with elevated serum C-reactive protein concentrations in normal to underweight breastfeeding women in Northern Kenya.

OBJECTIVES: Low-grade elevation of C-reactive protein (CRP) is a non-specific inflammatory marker, used as a predictor for cardiovascular disease development and chronic inflammatory risks. Research investigating dietary influences on inflammation has focused primarily on the relationship between dietary characteristics, CRP elevation and BMI in the populations at greatest risk for cardiovascular disease, namely those in the overweight and obese ranges, often in clinical settings and/or among those middle aged or older, leaving little information about normal to underweight populations of reproductive age in ecological settings. This study evaluates impacts of dietary nutrients on serum CRP levels in a population of predominantly underweight to normal weight adult women experiencing the additional nutritional demands of lactation. METHODS: Data from non-overweight breastfeeding Ariaal women of Kenya collected in 2006 were used (n = 194). Logistic regression models were applied using low-grade CRP elevation (hsCRP > 3 mg/L) as the outcome variable and dietary nutrients, age, BMI, and serum retinol as predictors. RESULTS: Models showed that energy intake (Kcal) and age were positive predictors of CRP elevation while folate intake, total vitamin A intake, and serum retinol concentration were protective against CRP elevation. Unlike previous studies among higher BMI populations, this study found no significant effect of dietary lipids/fatty acids or BMI on CRP elevation. CONCLUSIONS: The effects of specific dietary nutrients on inflammatory status may vary with BMI or, in women, reproductive status. Further research should investigate the role of dietary fats, fatty acids, and antioxidant vitamins across populations with a wide range of BMI, including postpartum women.

Process evaluation for a school-based physical activity intervention for 6th- and 7th-grade boys: reach, dose, and fidelity.

The purpose was to evaluate the reach, dose, and fidelity of Guys Only Activity for Life (G.O.A.L.), a 7-week pilot intervention conducted from February to March 2011 to increase 6th and 7th grade boys' moderate-to-vigorous physical activity (MVPA). One middle school was randomly assigned to the G.O.A.L. intervention and another from the same urban school district in the Midwestern U.S. to a comparison condition. Thirty boys, ages 10-14 years, participated in each school. The intervention, guided by the Health Promotion Model (HPM) and Self-Determination Theory (SDT), consisted of a 90-min after-school physical activity club 4 days/week and one motivational interviewing session with a registered (school) nurse. Data were gathered via attendance records, club observations, heart rate monitors, audio-taping of motivational interviewing sessions, and surveys. On average boys attended the club 2.11 days/week (SD=.86). A trained independent process evaluator reported that the physical activity club instructors provided the boys with the opportunity for a mean of 25.8 min/day of MVPA. Using a four-point Likert scale (1=disagree a lot; 4=agree a lot), the process evaluator perceived that the club was delivered with high fidelity and adherence to the underlying theories (M=3.48; SD=0.39). Sessions with the nurse lasted an average of 13 min, 29 s. All boys attended. Two trained independent coders indicated that the nurse demonstrated at least beginning proficiency for all tasks associated with motivational interviewing, with the exception of using sufficient open- as opposed to closed-ended questions and reflections compared to questions. Fidelity related to session delivery and adherence to the theories was high (M=3.83; SD=0.19). The process evaluation data indicated that strategies are needed to increase attendance and boys' MVPA during the club time.

Dietary diversity score is a useful indicator of vitamin A status of adult women in Northern Kenya.

OBJECTIVES: Diets consisting of diverse food items provide a wide range of nutrients that can enhance nutritional quality of the diet. Few studies have, however, assessed dietary diversity and its effects on micronutrient health in rural populations in field settings. This study assesses how well Dietary Diversity Score (DDS), an indicator of dietary diversity based on a simple count of food groups consumed, predicts the micronutrient status, focusing on serum vitamin A concentration. METHODS: We used cross-sectional data from women in food-insecure northern Kenya where dietary diversity is likely critical for micronutrient health yet under-studied. A linear regression model was applied to examine the relationships between DDS and serum retinol concentration. A logistic regression model was used to test DDS as a predictor of vitamin A insufficiency (serum retinol < 1.05 µmol/l). RESULTS: DDS had a significant positive effect on serum retinol concentration (t = 2.01, P = 0.045) after adjusting for age, wealth, acute phase reaction, hemoglobin, vitamin A intake and vitamin A supplementation. A one unit increase in DDS by adding an extra food group in one's diet was significantly less likely to have vitamin A insufficiency (OR = 0.64, P = 0.026) after adjusting for the covariates. CONCLUSIONS: Our results indicate that diversified diets enhance vitamin A status relative to narrower diets with equivalent vitamin A content. DDS shows a potential as a low-cost, field-friendly method for exploratory assessments of vitamin A status, and a potential as a research tool for human biologists and anthropologists interested in dietary quality and micronutrient health.

In poor families, mothers' milk is richer for daughters than sons: a test of Trivers-Willard hypothesis in agropastoral settlements in Northern Kenya.

The Trivers-Willard hypothesis predicts the unequal parental investment between daughters and sons, depending on maternal condition and offspring reproductive potential. Specifically, in polygynous populations where males have higher reproductive variance than females, it predicts that mothers in good condition will invest more in sons, whereas mothers in poor condition will invest more in daughters. Previous studies testing this hypothesis focused on behavioral investment, whereas few examined biological investment. This study investigates the Trivers-Willard hypothesis on both behavioral and biological parental investment by examining breastfeeding frequencies and breast milk fat concentrations. Data from exclusively breastfeeding mothers in Northern Kenya were used to test hypotheses: Economically sufficient mothers will breastfeed sons more frequently than daughters, whereas poor mothers will breastfeed daughters more frequently than sons, and economically sufficient mothers will produce breast milk with higher fat concentration for sons than daughters, whereas poor mothers will produce breast milk with higher fat concentration for daughters than sons. Linear regression models were applied, using breastfeeding frequency or log-transformed milk fat as the dependent variable, and offspring's sex (son = 1/daughter = 0), socioeconomic status (higher = 1/lower = 0), and the sex-wealth interaction as the predictors, controlling for covariates. Our results only supported the milk fat hypothesis: infant's sex and socioeconomic status interacted (P = 0.014, n = 72) in their relation with milk fat concentration. The model estimated that economically sufficient mothers produced richer milk for sons than daughters (2.8 vs. 1.74 gm/dl) [corrected] while poor mothers produced richer milk for daughters than sons (2.6 vs. 2.3 gm/dl). Further research on milk constituents in relation to offspring's sex is warranted.

Pilot intervention to increase physical activity among sedentary urban middle school girls: a two-group pretest-posttest quasi-experimental design.

The primary purpose of the study was to determine whether girls in one school receiving nurse counseling plus an after-school physical activity club showed greater improvement in physical activity, cardiovascular fitness, and body composition than girls assigned to an attention control condition in another school (N = 69). Linear regressions controlling for baseline measures showed no statistically significant group differences, but the directionality of differences was consistent with greater intervention group improvement for minutes of moderate to vigorous physical activity/hour (t = 0.95, p = .35), cardiovascular fitness (t = 1.26, p = .22), body mass index (BMI; t = -1.47, p = .15), BMI z score (t = -1.19, p = .24), BMI percentile (t = -0.59, p = .56), percentage body fat (t = -0.86, p = .39), and waist circumference (t = -0.19, p = .85). Findings support testing with a larger sample.

Vitamin A dynamics in breastmilk and liver stores: a life history perspective.

OBJECTIVES: Newborns are dependent on breastmilk vitamin A for building hepatic stores of vitamin A that will become critical for survival after weaning. It has been documented that vitamin A concentrations in breastmilk decline across the first year postpartum in both well-nourished and malnourished populations. The reason for this decline has been assumed to be a sign of concurrently depleting maternal hepatic stores. This study investigates this assumption to clarify why the decline occurs, drawing on life history theory. METHODS: A cross sectional survey was conducted among lactating mothers in Kenya in 2006. Data were used to examine (1) the relationship between liver vitamin A and time, (2) if the relationship between milk and liver vitamin A varies by time, and (3) by maternal parity. RESULTS: The relationship between liver vitamin A and time fits the quadratic pattern with marginal significance (P = 0.071, n = 192); the liver vitamin A declined during early postpartum then recovered in late postpartum time, controlling covariates. The milk-liver vitamin A relationship varied by postpartum time periods (P = 0.03) and by maternal parity (P = 0.005). Mothers in earlier postpartum or higher parity had a stronger positive relationship between milk and liver vitamin A than mothers in later postpartum or lower parity. CONCLUSIONS: Our observations are consistent with life history tradeoffs and negate the assumption that maternal hepatic and milk vitamin A decline together. Rather, maternal liver vitamin A has a dynamic relationship with milk vitamin A, particularly depending on postpartum time and maternal parity.

Mammography screening trends: the perspective of African American women born pre/post World War II.

Researchers have traditionally combined aging women (aged > or =50 years) when reporting their mammography use. This may inadvertently mask important cohort effects in mammography use, which are likely to result from distinct personal life experiences and generational differences. Using the Health and Retirement Study samples of 1998, 2000, and 2004, we examined cohort differences in mammography use between African American women born before 1946 (non-baby boomers) and those born in 1946 to 1953 (baby boomers). Between 1998 and 2004, screening rates for non-baby boomers declined, while those for baby boomers remained relatively steady. Hierarchical linear modeling (HLM) analyses suggest that while screening rates decreased with age (OR, 0.957; 95% CI, 0.947-0.968) cohort effects may have partially reversed the age effect, with non-baby boomers having an increased likelihood of receiving a mammogram compared to baby boomers (OR, 1.697; 95% CI, 1.278-2.254). Because African American women are diagnosed at later stages of breast cancer, documentation of cohort differences in mammography use among older African American women is important as health care professionals design intervention programs that are maximally effective for women from different cohorts. This is particularly critical as more African American women in the baby boomer cohort become part of the aging population.