Body composition through adult life: Swedish reference data on body composition.

BACKGROUND/OBJECTIVES: The prevalence of obesity, defined as body mass index (BMI) ⩾30 kg/m(2), differs between populations; however, there is a need for data on description on body composition in reference populations of different ages and from different countries. The objective of this study was to pool dual-energy X-ray absorptiometry (DXA) body composition reference data from population-based Swedish cohorts. SUBJECTS/METHODS: Four population-based cross-sectional cohort studies including 1424 adult Swedes were divided into five age groups (20-29, 30-39, 40-49, 50-61 and 75 years of age); BMI 24.6±3.9 kg/m(2) were pooled. Body composition was measured with DXA. RESULTS: The difference in BMI from the youngest to the oldest age group was 3.2 and 4.3 kg/m(2) in men and women, respectively (P<0.001, both sexes), and fat mass (FM) was 9.9 and 9.1% higher in the oldest compared with the youngest men and women (P<0.001, both sexes). Fat-free mass (FFM) remained stable up to 60 years of age in men (P=0.83) and was lower at 75 years of age compared with the younger ages. In women, FFM was lower from age 60. From youngest to oldest age groups, height-adjusted FM differed from 4.6 to 7.8 kg/m(2) in men and from 6.8 to 10.8 kg/m(2) in women (P<0.001, both sexes). CONCLUSIONS: Our results provide reference data on body composition in Swedish populations. BMI and FM were higher among older age groups compared with the younger ones. FFM remained stable up to 60 years of age and was lower first among the 75 years of age.

The genomic landscape underlying phenotypic integrity in the face of gene flow in crows.

The importance, extent, and mode of interspecific gene flow for the evolution of species has long been debated. Characterization of genomic differentiation in a classic example of hybridization between all-black carrion crows and gray-coated hooded crows identified genome-wide introgression extending far beyond the morphological hybrid zone. Gene expression divergence was concentrated in pigmentation genes expressed in gray versus black feather follicles. Only a small number of narrow genomic islands exhibited resistance to gene flow. One prominent genomic region (<2 megabases) harbored 81 of all 82 fixed differences (of 8.4 million single-nucleotide polymorphisms in total) linking genes involved in pigmentation and in visual perception-a genomic signal reflecting color-mediated prezygotic isolation. Thus, localized genomic selection can cause marked heterogeneity in introgression landscapes while maintaining phenotypic divergence.

Molecular phylogeny reveals a core clade of Rhytismatales.

Rhytismatales (Leotiomycetes, Pezizomycotina, Ascomycota) are an order of mostly plant-associated ascomycetes with a global distribution. Well known taxa include the Rhytisma tar spots on Acer spp. and several needle-cast pathogens in genera Lophodermium and Meloderma. Critical studies are lacking at all taxonomic ranks from order to species, and in particular the genus taxonomy in the order has been criticized for being unnatural. We used nuclear LSU and mitochondrial SSU sequences in Bayesian phylogenetic analyses to define a core clade of Rhytismatales sensu stricto. Some of the genera traditionally placed within the Rhytismatales, Ascodichaena, Marthamyces, Mellitiosporium, Potebniamyces, Propolis and Pseudophacidium, are shown to be phylogenetically distinct, all related to various other taxa at present placed in the polyphyletic Helotiales. Within the core clade only Cudonia, Spathularia and Terriera are supported as monophyletic. The large genera Coccomyces, Hypoderma and Lophodermium all are polyphyletic as are a few smaller genera. The traditionally used characters of ascoma and spore shape are shown to be unreliable for the delimitation of monophyletic genera but in some cases can be useful when combined with other characters. In this study we provide 72 new nrLSU and 64 new mtSSU sequences. Together with publicly available sequences data for 103 specimens representing 91 species of Rhytismatales are now available. Despite this taxon sampling intensity is still too low to propose an alternative generic taxonomy.

Body composition in a cohort of Swedish adolescents aged 15, 17 and 20.5 years.

OBJECTIVE: To assess variables of body composition and identify their correlates in a group of individuals studied from adolescence to early adulthood. METHODS: Cross-sectional results were obtained from 203, 149 and 106 subjects at the respective ages. Sixty-two subjects examined at all three ages constituted the longitudinal study group. A cohort of randomly selected 15-year-old adolescents from an industrial town in Sweden was studied by dual energy X-ray absorptiometry (DXA) and followed up at 17 and 20.5 years. Lean body mass (LBM), fat mass (FM) and total body bone mineral content (TBMC) were measured by DXA. Total bone mineral density (TBMD) was calculated. Information of parental educational level, energy intake and food habits, energy expenditure (TEE) and physical activity level (PAL) was obtained by questionnaires and diaries. RESULTS: LBM, TBMC and TBMD increased significantly more in males and FM more in females, from 15 to 20.5 years of age. Body weight, height, TEE, PAL and the fathers' educational level and, at age 15, also gender were identified as significant correlates of the body composition variables. CONCLUSION: New reference values for body composition at ages 15, 17 and 20.5 years are presented and also a finding about an association between the father's educational level and the adolescent's body composition.

Intermittent versus on-demand use of a very low calorie diet: a randomized 2-year clinical trial.

OBJECTIVES: To compare two different very low calorie diet (VLCD)-based weight maintenance strategies. DESIGN AND SETTING: A randomized 2-year clinical trial performed at the Department of Body Composition and Metabolism, Sahlgrenska University Hospital, Sweden. SUBJECTS: A total of 334 patients, body mass index (BMI) >30 kg m-2, aged 18-60 years. INTERVENTIONS: All the patients started with 16 VLCD weeks. Subjects in the intermittent group were then scheduled to use VLCD for 2 weeks every third month, whilst patients in the on-demand group were instructed to use VLCD whenever their body weight passed an individualized cut-off level. Irrespective of the treatment group, all the subjects were recommended a hypocaloric diet during VLCD-free periods. MAIN OUTCOME MEASURES: Changes in body weight, body composition, anthropometric variables and cardiovascular risk factors. RESULTS: Completers in both groups maintained highly significant weight losses after 2 years: 7.0 +/- 11.0 kg (6.2 +/- 9.5%) in the intermittent group and 9.1 +/- 9.7 kg (7.7 +/- 8.1%) in the on-demand group (P < 0.001, ns between groups). Male completers in the on-demand group lost significantly more weight than men in the intermittent group, 14.5 +/- 11.0 kg vs. 4.0 +/- 10.5 kg, respectively (P < 0.01). Most cardiovascular risk factors improved during the first year, whilst anthropometric measures, insulin, HDL- and LDL-cholesterol were also significantly improved after 2 years of treatment. CONCLUSION: Clinically significant weight reductions were achieved after 2 years of VLCD-based treatment. The structure of VLCD treatment during the maintenance phase did not affect weight loss in the total study population, whilst male subjects might benefit from the VLCD on-demand strategy.

Whole-body mineral measurements in Swedish adolescents at 17 years compared to 15 years of age.

AIM: To provide reference data for bone mineral variables in 15- and 17-y-old adolescents and to analyse the relationships between these variables and measures of bone and body size, gender, puberty, growth, various lifestyle and environmental factors and socioeconomic background. METHODS: In the same 321 randomly selected adolescents (147 boys and 174 girls) living in two different regions of Sweden, the total bone mineral content (TBMC), bone area (BA) and total bone mineral density (TBMD) were assessed by dual-energy X-ray absorptiometry at ages 15 and 17 y. The effects of bone and body size, gender, growth, sexual maturity, physical activity, region of domicile, social conditions, food habits, smoking and alcohol intake on TBMC and TBMD were examined in multivariate analyses. RESULTS: In the 15-y-old adolescents, BA, height, gender, physical activity, maturity and weight explained 91% and 48%, of the variance in TBMC and TBMD, respectively. In similar analyses in the 17-y-olds, the corresponding figures were 92% and 62%, respectively, when BA, height, growth, physical activity, gender and region emerged as significant in the model. In all these analyses, BA explained most of the variance in TBMC and TBMD. No significant reduction of variance was found when different measures of social conditions, smoking, food habits, alcohol or dietary intakes of energy, calcium or vitamin D were included in the models. The reason why region of domicile had a significant impact on TBMC in the 17-y-olds is not known. The fact that the normal fluoride concentration in drinking water (1.1 mg/L) is 10 times higher in the region where TBMC was higher than in the other region is an interesting observation. CONCLUSION: Almost 90% of the variance in TBMC and 50% of that in TBMD was explained by measures of bone and body size and only a few percent by gender, physical activity, Tanner stage, growth and region of domicile.

Differences in whole body measurements by DXA-scanning using two Lunar DPX-L machines.

OBJECTIVE: To compare bone mineral and body composition results of two dual-energy X-ray absorptiometry (DXA) instruments from the same manufacturer. SETTINGS: The Medical departments of Sahlgrenska University Hospital, Göteborg and University Hospital, Uppsala, Sweden. DESIGN: Unique aluminium spine phantoms (Phant A and B) delivered with each DXA machine (DXA-A and DXA-B) were cross-checked on the other machine by using the 'AP spine mode'. Eight adolescents were examined on both instruments within 5 h to ascertain total body variables by using standard, as well as extended, modes of analysis. All these double-examinations were undertaken on two occasions, before and after exchange of a detector on the DXA-B. SUBJECTS: Four males and four females aged 15.4-19.2 y with normal body weights, were examined on both occasions. On each occasion, the first examination was performed in Göteborg on four individuals and in Uppsala on four individuals. RESULTS: On the first occasion the phantom measurements resulted in much lower bone mineral density (BMD) values on the DXA-B than on the DXA-A. Later it was detected that a so-called R-value and the corresponding '%-fat' value were out of range on the DXA-B. After exchange of detector, the difference in phantom BMD-values between the two machines had diminished. On the first occasion in vivo BMD values were lowest on the DXA-B (P < 0.01), while on the second occasion they were significantly lower on the DXA-A (P < 0.05). Soft tissue differences were greater after detector exchange and as compared to DXA-A, DXA-B underestimated body fat by 3.5 kg (13.2 vs 9.7 kg, P < 0.001) and overestimated lean tissue mass by 3.8 kg (47.1 vs 50.9 kg, P < 0.001) on the second occasion. CONCLUSIONS: The differences in results between two apparently identical Lunar DPX-L machines were not acceptable. In multicenter studies, it may be necessary to standardise results of participating machines into results of one machine by means of regression equations obtained by examining subsamples of individuals on one master machine and other participating instruments.

More characters or more taxa for a robust phylogeny--case study from the coffee family (Rubiaceae).

Using different data sets mainly from the plant family Rubiaceae, but in parts also from the Apocynaceae, Asteraceae, Lardizabalaceae, Saxifragaceae, and Solanaceae, we have investigated the effect of number of characters, number of taxa, and kind of data on bootstrap values within phylogenetic trees. The percentage of supported nodes within a tree is positively correlated with the number of characters, and negatively correlated with the number of taxa. The morphological analyses are based on few characters and weakly supported trees are expected. The percentage of supported nodes is also dependent on the kind of data analyzed. In analyses of Rubiaceae based on the same number of characters, RFLP data give trees with higher percentage of supported nodes than rbcL and morphological data. We also discuss the support values for particular nodes at the familial and subfamilial levels. Two new data sets of ndhF and rbcL sequences of Rubiaceae are analyzed and together with earlier studies of the family we can conclude that the monophyly of the Rubiaceae is supported and within the family there are three well supported, but not easily characterized, large subfamilies, Rubioideae, Cinchonoideae s.s. and Ixoroideae s.l. There are also a few genera (Luculia and Coptosapelta) unclassified to subfamily.

Computed tomography-determined body composition in relation to cardiovascular risk factors in Indian and matched Swedish males.

Relationships between cardiovascular risk factors, body composition, and tissue distributions were examined in 10 Indian and 10 Swedish males matched by age, height, and weight. The body was divided into 29 compartments by means of a multiscan computed tomography (CT) technique. Fasting glucose, insulin, and triglycerides (TG) were higher in Indians than in Swedes. During the oral glucose tolerance test (OGTT), the glucose area was similar in both groups, whereas the insulin area was 80% larger in Indians. Adipose tissue (AT) and skin volumes were larger and remaining lean tissues were smaller in Indians. Indians had proportionally less muscle and more skeleton in the legs, but no ethnic difference could be demonstrated with respect to AT distribution. The visceral AT to total AT volume ratio was positively related to insulin and TG, and with higher risk factors for Indians at any given ratio. TG and glucose were negatively related to the leg muscle to total muscle volume ratio, and this ratio was smaller in Indians. It is concluded that the metabolic disturbances of Indians are not necessarily dependent on a preponderance of visceral AT, and also that an upper-body muscle distribution-recognized as a new phenotypic companion to the metabolic syndrome-is statistically related to cardiovascular risk factors.

Giant cell tumor of the larynx.

A case of giant cell tumor of the larynx is reported. Only two previous cases were reported in the English literature. A review of giant cell tumors is reported. The specific pathologic findings and treatment recommendations for this condition are discussed.

Surgical correction of choanal atresia in the neonate.

The purpose of this paper is to present a technique of endonasal puncture and stenting for bilateral choanal atresia in the neonate that is easily performed and may be definitive. The procedure described is original only in its details, its broad principles are well known. A method of placing the nasal stent is reported that is particularly applicable in the premature, even as small as five pounds. No antibiotics or steroids are given in the postoperative period. Three months is the recommended duration of stenting. Four patients were operated on using this technique, between July 1978 and August 1979; 3 were complete successes; 1 was a bilateral failure, but was re-operated on and was then a unilateral success. Shortest follow-up was 16 months. We feel endonasal puncture and stenting of bilateral choanal atresia in the neonate can be definitive, and is the first procedure of choice.