Lack of consistency in the indirect methods of estimating percent body fat

Several studies have emphasized the relationship between body composition and the initiation and/or maintenance of cyclic ovarian function in women. A number of methods of indirectly calculating percent body fat have been used, but there is no clear evidence that the various calculations produce consistent results. We therefore compared five different ways of estimating the "percent body fat" in a total of 18 young women, including 6 normal control subjects who did not exercise, 6 regularly menstruating runners, and 6 amenorrheic runners. There was considerable individual variation in the estimates of body fat; and significant differences among groups were found by some, but not all, methods of calculation. It is suggested that because of the inconsistency of estimates, the use of the term "percent body fat" is misleading and that opposite conclusions may result from the use of different methods of calculating body fat in the same groups of individuals.     

Endocrine comparison of obese menstruating and amenorrheic women

10 examine the relationship between obesity and chronic anovulation, we compared basal serum LH, FSH, and PRL levels, determined at 20-min intervals, and basal C21 [progesterone, 17- hydroxyprogesterone , pregnenolone, 17-hydroxypregnenolone ( 17Pe ), and cortisol], C19 [testosterone (T), delta 4-androstenedione (A), and dehydroepiandrosterone] and C18 (estrone and estradiol) steroid hormone concentrations measured at 1- to 2-h intervals for a 24-h period in five normal weight cycling women (NC) and in two groups of weight-matched obese women. Five of the obese women were regularly cycling (OC), and six were amenorrheic (OA). Sex hormone-binding globulin (SHBG) and non-SHBG-bound T and estradiol concentrations were also measured in each woman. Compared to NC women, OC women had normal basal protein and steroid hormone concentrations, except for reduced 17Pe levels (P less than 0.05). Mean SHBG concentrations were reduced by approximately 30%, and non-SHBG-bound T was increased by 70%, although the differences were not significant. In addition, when six precursors of testosterone (pregnenolone, 17Pe , dehydroepiandrosterone, progesterone, 17-hydroxyprogesterone, and A) were considered together as a group and the data analyzed by the kappa 2 test, a reduction in basal levels of these precursors was found in OC women relative to those in NC women (P less than 0.005). In OA women, mean concentrations of SHBG were markedly reduced and those of total T, A, estrone, and non-SHBG-bound T were significantly increased compared to those in both NC and OC women. Mean 24-h concentrations of LH tended to be greatest and FSH lowest in this group, but were not significantly different from those in the other groups. The mean LH pulse frequency was significantly greater in OA than in OC women (P less than 0.05). Mean 24-h PRL and cortisol levels were also reduced in OA women relative to those in NC women. These data suggest the possibility of a compensatory decline in total T production in OC women in an attempt to maintain normal hormonal homeostasis; as a consequence, ovulation continues in a cyclic fashion. In OA women, such compensatory mechanisms are no longer operative. Instead, a central and/or peripheral defect, resulting in overproduction of androgen, may also exist and lead to anovulation in OA women. In conclusion, our data imply that obesity is not a primary factor causing chronic anovulation. However, obesity may aggravate an already existing subtle defect in some women and result in amenorrhea.     

Luteal phase estrogen is decreased in regularly menstruating older women compared with a reference population of younger women

OBJECTIVE: To compare daily reproductive hormone secretion in regularly menstruating older versus younger women. DESIGN: This was a prospective cohort study. RESULTS: Daily morning urine samples were obtained from 106 women, 28 of whom were aged between 20 and 34 years (mean: 27.8+/-3.7 y) and 78 of whom were aged between 35 and 50 years (mean: 40.3+/-3.7 y). Lower luteal estrone-3-glucuronide levels were seen in the older versus the younger group (82.7 vs 93.5 ng/ml, P=0.035). The pregnanediol-3-glucuronide levels in the older group were lower than those in the younger group throughout the entire cycle. The median length of the follicular phase was shorter in the older versus younger women (13 vs 14.5 d, P=0.005). There was no significant difference in the median luteal phase lengths between groups. CONCLUSIONS: We report the new finding that regularly menstruating older women not only have lower pregnanediol-3-glucuronide levels but also have a significant reduction in luteal phase estrone-3-glucuronide compared with a contemporaneous cohort of younger women. This combined deficit may play a key role during the luteal-follicular transition, potentially affecting follicle recruitment and decreasing fecundity in the subsequent cycle.     

Psychometric Evaluation of the Brunei-Malay SF-36 version 2 Health Survey

Objectives: To culturally adapt the Short Form Health-36 version 2 (SF-36v2) into the Brunei-Malay context anddetermine its reliability and validity for measuring health-related quality of life (HRQOL) in healthy individuals andpatients with chronic kidney disease in Brunei Darussalam. Methods: An iterative multistep strategy involving setting upa bilingual expert panel, pretesting, text revision and back translation was used to prepare the Brunei-Malay SF-36v2 asan adaptation from the Malaysian-Malay SF-36v2. The Brunei-Malay SF-36v2 was then self-administered to a sample ofhealthy individuals (n=95) and predialysis chronic kidney disease outpatients (n=95) resident in Brunei. The mean(SD) age of the participants was 46.6 (17.8) years. Results: Data completion rate was 100% with minimal floor effects(≤0.21) in all the 8 domains and >15% ceiling effects in 3 of the 8 domain scales. Cronbach’s alpha was >0.70 for allthe 8 domain scales. Scaling success was 100% for convergent validity, with 100% item discriminant validity for alldomain scales except Social Functioning (94%), Mental Health (85%) and General Health (85%). Principal componentanalysis of the two-factor dimension explained 68% overall variance and accounted for 81% reliable variance, but theexact SF-36 two-factor summary constructs in the standard algorithm were not replicated in the Bruneian population.Conclusions: The Brunei-Malay SF-36v2 is a valid and reliable instrument for measuring HRQOL in healthy individualsand patients with chronic kidney disease in Brunei. The summary scales should, however, be interpreted with caution.Further studies should be carried out to assess additional psychometric properties of the Brunei-Malay SF-36v2.     

Eating practices and behavior in the urban environment: a study in downtown São Paulo

This study focuses on the implications of urban life style on eating habits and the related symbolic representations. Theoretical references used to approach the food experience are the concepts of social representation and habitus. The methodology consisted of a qualitative analysis of interviews with 21 administrative employees and field observations made at commercial establishments in downtown S?o Paulo, such as snack bars and restaurants. Study of eating behavior and practices was developed along two planes: food actually eaten and food desired. Results were classified into three segments: "ingesting and digesting affection", "determinants of social representations of eating practices", and "rituals in eating practices". Due to their origin in a domestic universe, symbolic aspects associated with food have a strong affective matrix. Concrete conditions of the urban environment associated with the subject's financial limits establish a structure of values and feelings compatible with the subject's possibilities. The study addresses both the abbreviation of food rituals and its implications on food behavior as well as features of the present urban food pattern.     

Does a single control mechanism exist for both forward and backward walking?

It has been proposed that the highly reproducible forward walking (FW) locomotor pattern is generated by a central neuronal program or central pattern generator (CPG) which provides the underlying mechanism which produces the coordinated walking movement. The purpose of this study was to quantify the differences in the muscular activation patterns during FW and backward walking (BW) at a constant step frequency and to determine if common features exist across both locomotor conditions. The hypothesis was that FW and BW are both mediated by the same CPG; therefore, only small modifications in the CPG are required in order to produce the different characteristics of each walking mode. The results noted kinematically reversed patterns at the hip and ankle joints between FW and BW. The knee joint movement pattern was similar between conditions, however, a phase shift of 14.3% of the gait cycle occurred. An approximately 25% phase shift in the muscle activation patterns existed between FW and BW in four of the six muscles studied. Additionally, a pattern recognition technique was applied to the combined EMG signals to determine the minimum number of features required to generate the measured muscular output. Only two main features were necessary to produce the EMG patterns for both the FW and BW condition. The main features in FW were more consistent than noted in BW. The results support the notion that a single spinal mechanism such as a CPG with two main features appears to be in control during both FW and BW.     

A biotin-streptavidin enzyme immunoassay for detection of antibodies to porcine granulosa cell antigens.

A colorimetric solid-phase enzyme immunoassay has been developed which quantifies antibodies to porcine granulosa cell membrane antigens in rabbits immunized with porcine granulosa cells. A cell-free, particulate membrane preparation of porcine granulosa cells was used as coating antigen. A biotinylated second antibody in conjunction with a streptavidin-beta-galactosidase conjugate was utilized to amplify reactivity. The enzyme beta-galactosidase was used due to high background obtained using peroxidase, presumably due to endogenous peroxidase activity of the tissue. Sigmoidal serum dilution curves were obtained with immune rabbit sera indicating that absorbance was related to the concentration of antibodies. Assay activity was reduced by preincubation of immune serum with granulosa cell membranes. Sera from ovariectomized or pre-immune rabbits did not yield any specific binding in the assay. This assay has potential applicability for quantifying antiovarian and antigranulosa cell antibodies in women suspected of having autoimmune premature ovarian failure.     

The facilitators and barriers of physical activity among Aboriginal and Torres Strait Islander regional sport participants

Background : Disparities in health perspectives between Indigenous and non‐Indigenous populations are major concerns in many of the world's well‐developed nations. Indigenous populations are largely less healthy, more prone to chronic diseases, and have an earlier overall mortality than non‐Indigenous populations. Low levels of physical activity (PA) contribute to the high levels of disease in Indigenous Australians. Method : Qualitative analysis of structured one‐on‐one interviews discussing PA in a regional setting. Participants were 12 Indigenous Australian adults, and 12 non‐Indigenous Australian adults matched on age, sex, and basketball division. Results : Most participants reported engaging in regular exercise; however, the Indigenous group reported more barriers to PA. These factors included cost, time management and environmental constraints. The physical facilitators identified by our Indigenous sample included social support, intrinsic motivation and role modelling. Conclusion : Findings describe individual and external factors that promote or constraint PA as reported by Indigenous Australian adults. Results indicate that Indigenous people face specific barriers to PA when compared to a non‐Indigenous sample. Implications for public health: This study is the first to compare the perspective of Indigenous Australians to a matched group of non‐Indigenous Australians and provides useful knowledge to develop public health programs based on culturally sensitive data.