Juliann K. Martel

Dietary assessment using a picture-sort approach

Food-frequency questionnaires are usually administered as a list of foods to be checked off by the respondent or interviewer. Techniques in which participants sort into categories cards on which names or pictures of foods are printed can also be used to assess food intake. Food-frequency scores were obtained from a five-category picture sort administered to 4643 men and women aged > or = 65 y in the Cardiovascular Health Study (CHS). This one-step (qualitative) assessment yielded significant associations in expected directions between frequency scores and sex, age, race or ethnicity, body mass index, and use of a special diet. In the two-step (semiquantitative) version of this instrument, an interviewer documented specific frequencies and portion-size information for the foods in each sorting category. A substudy of the two-step version with 96 CHS participants indicated relative validity similar to that of conventionally administered food-frequency questionnaires. The one-step version may be broadly applicable to situations in which general food-pattern data can be informative and cost and time limitations are great. When it is feasible, the two-step picture sort may offer certain methodologic advantages because respondents have a chance to change their responses and the format may simplify the cognitive-response task. Sorting or picture-sort procedures deserve systematic attention in research on dietary assessment methods.

The effect of calcium supplementation and tanner stage on bone density, content and area in teenage women

One hundred and twelve Caucasian girls, 11.9±0.5 years of age at entry, were randomized into a 24-month, double-masked, placebo-controlled trial to determine the effect of calcium supplementation on bone mineral content, bone area and bone density. Supplementation was 500 mg calcium as calcium citrate malate (CCM) per day. Controls received placebo pills, and compliance of both groups averaged 72%. Bone mineral content, bone mineral area and bone mineral density of the lumbar spine and total body were measured by dual energy X-ray absorptiometry (DXA). Calcium intake from dietary sources averaged 983 mg/day for the entire study group. The supplemented group received, on average, an additional 360 mg calcium/day from CCM. At baseline and after 24 months, the two groups did not differ with respect to anthropometric measurements, urinary reproductive hormone levels or any measurement of pubertal progression. The supplemented group had greater increases of total body bone measures: content 39.9% versus 35.7% (p=0.01), area 24.2% versus 22.5% (p=0.15) and density 12.2% versus 10.1% (p=0.005). Region-of-interest analyses showed that the supplemented group had greater gains compared with the control group for bone mineral density, content and area. In particular, in the lumbar spine and pelvis, the gains made by the supplemented group were 12%–24% greater than the increases made by the control group. Bone acquisition rates in the two study groups were further compared by subdividing the groups into those with below- or above-median values for Tanner score and dietary calcium intake. In subjects with below-median Tanner scores, bone acquisition was not affected by calcium supplementation or dietary calicum level. However, the calcium supplemented subjects with above-median Tanner had higher bone acqusition rates than the placebo group with above-median Tanner scores. Relative to the placebo group, the supplemented group had increased yearly gains of bone content, area and density which represented about 1.5% of adult female values. Such increases, if held to adult skeletal maturity, could provide protection against future risk of osteoporotic fractures.

A WEIGHTED CONCORDANCE CORRELATION COEFFICIENT FOR REPEATED MEASUREMENT DESIGNS

The need to quantify agreement between two raters or two methods of measuring a response often arises in research. Kappa statistics (unweighted and weighted) are appropriate when the data are nominal or ordinal, whereas the concordance correlation coefficient is more appropriate when the data are measured on a continuous scale. We develop weighted product-moment and concordance correlation coefficients which are applicable for repeated measurements study designs. We consider two distinct situations in which the repeated measurements are paired or unpaired over time. We illustrate the methodology with examples comparing (1) two assays for measuring serum cholesterol, (2) two estimates of dietary intake, from a food frequency questionnaire and dietary recalls, and (3) two measurements of percentage body fat, from skinfold calipers and dual energy x-ray absorptiometry.

Role of polyamines in the growth of hormone-responsive and - resistant human breast cancer cells in nude mice

Recent in vitro data suggest that at least some hormone-independent breast cancer cells exhibit increased polyamine biosynthesis and resistance to antipolyamine therapy. To address this issue under conditions of in vivo growth, we tested the antiproliferative effect of the polyamine synthetic inhibitor alpha-difluoromethyl-ornithine (DFMO) on hormone-dependent (MCF-7) and -independent (MDA-MB-231, BT-20) breast cancer cell lines growing in nude mice. We observed that DFMO significantly inhibited the growth of established tumors to a similar extent in all cell lines, even though tumor regression was only observed with MCF-7 cells. DFMO, while inhibiting E2-supported MCF-7 breast cancer growth, did not inhibit E2-stimulated progesterone receptor synthesis. Cellular levels of polyamines were highest in MCF-7 cells and lowest in the BT-20 cell line. Tumor content of spermidine was similarly suppressed by DFMO treatment in the 3 cell lines, while the spermine level was unaffected. Cellular putrescine levels were suppressed in MCF-7 and BT-20 cells. Administration of DFMO prior to implantation of fragments of MCF-7 or MDA-MB-231 tumors in nude mice significantly inhibited tumor development to a similar extent. The action of DFMO seemed to be predominantly tumoristatic since new tumors develop in some mice upon discontinuation of the drug. We conclude that the hormone-independent breast cancer cell lines tested do not exhibit increased polyamine biosynthesis or resistance to antipolyamine therapy when grown in vivo in nude mice.

PEDIATRIC PREVENTIVE HEALTH SCREENING AND DIETARY INTAKE

Abstract As part of a program evaluating nutrition education for hypercholesterolemic children, a pediatric practice-based cholesterol screening program identified 261 3.9–9.9 year old children with elevated cholesterol levels (At-Risk). At baseline (before any intervention), the diets of these children were found to be relatively low in fat (29.7% calories as fat, and 11.2% as saturated fat). This is approaching recommended levels and is lower than has been reported for similar groups of children. To help evaluate potential influences upon the dietary intake of these At-Risk children, their diets were compared to the diets of children without elevated cholesterol levels (Not-At-Risk, n=81). The diets of the Not-At-Risk children were then compared to a group of children who had not completed cholesterol screening nor dietary intervention (not-screened, n=49). Three 24-hour dietary recalls were completed by telephone with each child at baseline and averaged. These recalls and subsequent comparisons showed that the only statistically significant differences between the groups were a lower caloric intake and fiber intake for the At-Risk group as compared to the Not-At Risk group. These results suggest that some groups of American children are consuming a diet with fat, saturated fat and cholesterol content closer to recommended levels than previously reported. In addition, participation in preventive health screening, such as a cholesterol screening program and being labelled as hypercholesterolemic, seemed to have little influence on the intake of fat, saturated fat or cholesterol.

ONE YEAR FOLLOW-UP OF NUTRITION EDUCATION FOR HYPERCHOLESTEROLEMIC CHILDREN† 581

The efficacy of an innovative home-based, physician-initiated parent-child autotutorial nutrition education program (PCAT) and of standard nutrition counseling for hypercholesterolemic children were evaluated. Two-hundred-sixty-one 3.9-9.9 year old children with elevated LDL cholesterol(LDL-C) levels were randomly assigned to one of the nutrition interventions, or to an At-Risk Control group. A Not-At-Risk Control group of children with normal cholesterol levels was also recruited (n=81). The change in knowledge of heart healthy foods, dietary intake, and (for the At-Risk groups only) blood lipid levels were evaluated at 3, 6 and 12 months post-baseline. The PCAT group exhibited a significant initial increase in knowledge of heart healthy foods, which was fully retained. The PCAT and Counseling groups lowered their total fat and saturated fat intake throughout the year. The PCAT groups decrease in LDL-C level at 3 months reached borderline significance, when compared to the At-Risk Control group. This trial demonstrated that knowledge and dietary change can be affected and retained via an innovative home-based nutrition intervention for children, though some form of ongoing intervention may be necessary to produce lasting decreases in LDL-C level.

USEFULNESS OF SEQUENTIAL URINE FSH AND LH MEASUREMENTS IN THE DIAGNOSIS OF ADOLESCENT-AGED HYPOGONADOTROPISM

Urine concentrates assessed by RIA provide as sensitive a methodology for gonadotropin measurements as newly available immunofluorometric techniques. The ease of obtaining repeated, short-term (3-6hr), timed urine specimens and allowing the kidney to integrate for pulsatile secretion lends itself to distinguishing patients with gonadotropin deficiency from those with constitutional delay in adolescence. We have compared the rate of gonadotropin rise in males between the ages of 12-18 yrs. in 48 normal boys, 96 patients with constitutional delay, 19 patients with isolated gonadotropin deficiency, and 10 patients with multiple tropic hormone deficiency. A total of 511 specimens were analyzed by a longitudinal model that allowed for separate intercepts and linear slopes on log transformed data for each of the four diagnostic categories. For LH, the linear equation describing the constitutional group was log LH=0.6 + 0.32 x age (p<0.0001 for slope of line) but for the isolated hypogonadotropic patients was log LH=4.14 + 0.03 x age (p=0.74). Using a Bonferroni correction, the rate of hormone increase was markedly different for the constitutional delayed boys as compared to the hypogonadotropic patients (p=0.02). Similar findings existed for FSH. The model utilized provides a guide for determining the appropriate diagnosis for a patient with delayed adolescence who is followed for a year or more with sequential gonadotropin determinations. In conclusion, a separation of adolescent boys with hypogonadotropism from those who have constitutional delay can be made by following sequential urine gonadotropin determinations over a year or more.