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Biomedical subjects

Joan M Lappe

Publications and source records attributed to Joan M Lappe.

6 recordsLinked to original sources
PubMed2006

Vitamin D status in a rural postmenopausal female population.

BACKGROUND: Inadequate vitamin D nutritional status is increasingly recognized as common in North American and European populations, but the extent of the shortfall and the parameters of the distribution for populations of interest remain uncertain. PURPOSE: To report the distribution of values for serum 25-hydroxyvitamin D [25(OH)D] in a population of rural postmenopausal women, together with quantification of factors related to vitamin D status. SETTING: Nine largely agrarian counties in eastern Nebraska (approximately 41 degrees N). PARTICIPANTS: A population-based sample of 1,179 women 55 years of age and older recruited into a four-year trial of calcium and vitamin D supplementation. METHODS: Baseline biochemical, dietary, and anthropometric measurements obtained on entry into trial. RESULTS: Serum 25(OH)D concentration at baseline varied cyclically with season, with the solar cycle explaining 2.9% of the total variance (P < 0.001). Mean seasonally adjusted 25(OH)D concentration was 71.1 nmol/L. Serum 25(OH)D also exhibited the expected inverse curvilinear relationship with serum parathyroid hormone (PTH), with the inflection point of the curve located at approximately 80 nmol/L. Supplements containing vitamin D were regularly taken by 59% of the cohort (median dose: 200 IU/d). Nevertheless, approximately 4% of all women had values below the laboratory reference range and more than two-thirds fell below 80 nmol/L. Seasonally adjusted serum 25(OH)D concentration was positively correlated with the size of daily vitamin D supplement dose, and negatively with age, weight, and body mass index (P < 0.01 for all). In stepwise multiple linear regression models, weight, age, and supplement dose were independently correlated with seasonally adjusted serum 25(OH)D, and together explained 19% of the total variance of adjusted 25(OH)D concentration. Women taking supplements had only one-sixth the chance of having a 25(OH)D value below the reference limit of the assay, compared to women who did not use supplements. CONCLUSIONS: Approximately two-thirds of this rural population fell below 80 nmol/L, a value considered to be the lower end of the optimal range. Based on the slope of 25(OH)D on supplement dose observed in these women, it would require an additional vitamin D input of nearly 2000 IU/d to reach the goal of an RDA for vitamin D, i.e., to bring 97.5% of the cohort to levels of 80 nmol/L or higher.

Aged↗
PubMed2006

Accuracy of pubertal Tanner staging self-reporting.

OBJECTIVES: Previous studies examining the reliability of self-reported Tanner stages have given conflicting results. We report on the reliability of self-reported Tanner stages in lean healthy children. METHODS: Self-reported Tanner staging of 240 children (130 girls, 110 boys) were compared to the ratings of a pediatric endocrinologist who was unaware of the children's self-assessments. The correlation between the two approaches was analyzed using kappa statistics. RESULTS: 40% (kappa coeffcient = 0.49, p <0.001) and 23% (kappa coefficient = 0.68, p <0.001) of the girls rated their breast and pubic Tanner stage incorrectly, respectively; 39% of the boys (kappa coefficient = 0.49, p <0.001) rated their pubic stage incorrectly. The age of the children who self-rated correctly and incorrectly was not different; no independent predictors for correct Tanner staging self-assessment were found. CONCLUSIONS: The results of this analysis suggest that self-rated Tanner pubertal staging is not influenced by age and is not a reliable method of assessing Tanner stage.

Adolescent↗
PubMed2005

A novel pathophysiological mechanism for osteoporosis suggested by an in vivo gene expression study of circulating monocytes.

Bone mineral density (BMD) is a major risk factor for osteoporosis. Circulating monocytes may serve as early progenitors of osteoclasts and produce a wide variety of factors important to bone metabolism. However, little is known about the roles of circulating monocytes in relation to the pathophysiology of osteoporosis. Using the Affymetrix HG-U133A GeneChip(R) array, we performed a comparative gene expression study of circulating monocytes in subjects with high and low BMD. We identified in total 66 differentially expressed genes including some novel as well as some already known to be relevant to bone metabolism. Three genes potentially contributing to bone metabolism, CCR3 (chemokine receptor 3), HDC (histidine decarboxylase, i.e. the histamine synthesis enzyme), and GCR (glucocorticoid receptor), were confirmed by quantitative real-time reverse transcriptase-PCR as up-regulated in subjects with lower BMD. In addition, significant negative correlation was observed between expression levels of the genes and BMD Z-scores. These three genes and/or their products mediate monocyte chemotaxis, histamine production, and/or sensitivity to glucocorticoids. Our results suggest a novel pathophysiological mechanism for osteoporosis that is characterized by increased recruitment of circulating monocyte into bone, enhanced monocyte differentiation into osteoclasts, as well as osteoclast stimulation via monocyte functional changes. This is the first in vivo microarray study of osteoporosis in humans. The results may contribute to identification of new genes and their functions for osteoporosis and suggest genetic markers to discern individuals at higher risk to osteoporosis with an aim for preventive intervention and treatment.

Aged↗
PubMed2005

Why blame milk?

Explore the source record for details and available documents.

Adolescent↗
PubMed2004

Girls on a high-calcium diet gain weight at the same rate as girls on a normal diet: a pilot study.

OBJECTIVE: To determine whether pubertal girls assigned to calcium-rich diets or their usual calcium intakes differ significantly in weight gain. DESIGN: This is a pilot study conducted on data from an experimental research project. SUBJECTS/SETTING: The sample included 59 girls, 9 years of age, from Omaha metropolitan communities. INTERVENTION: Participants were randomly assigned to a calcium-rich diet supplying at least 1,500 mg of calcium per day or their usual diet. MAIN OUTCOME MEASURE: The outcome measure was change in weight during 2 years of study. STATISTICAL ANALYSES: Data were analyzed using descriptive statistics, Mann-Whitney U, t tests of paired and independent samples, and analysis of covariance. RESULTS: The girls in the calcium-rich diet group had a mean (+/-standard deviation) calcium intake of 1,656+/-191 mg/day, whereas the girls on their usual diets averaged 961+/-268 mg/day. Although the participants in the treatment group consumed nearly twice as much dietary calcium--primarily from dairy foods--they did not have greater increases in body weight, body mass index, or fat or lean mass than the control group. These findings held when the data were grouped by tertile of calcium intake. Compared with girls on their usual diets, the girls who consumed the calcium-rich diet also significantly increased their intake of essential nutrients. CONCLUSION: We conclude that calcium-rich diets do not cause excessive weight gain in pubertal girls but do contribute positively to overall nutrition. These findings provide support for programs to promote calcium-rich diets, which are critical for attaining peak bone mass.

Absorptiometry, Photon↗