Cerebral function in perinatally HIV-infected young adults and their HIV-uninfected sibling controls

Background:

Perinatally acquired HIV-infected (PaHIV) young adults undergo neurodevelopment in the presence of HIV infection and antiretroviral therapy, which may lead to neurocognitive (NC) impairment. Knowledge of NC function in this group is sparse and control data lacking. We compared cerebral function in young adults with PaHIV infection to aged matched HIV negative family controls.

Methods:

16–25-year-old PaHIV young adults (Group 1, n?=?33) and HIV-uninfected family controls (Group 2, n?=?14) were recruited. Cerebral function was evaluated by: a computerized battery assessing NC function (CogState^TM), International HIV Dementia Scale (IHDS) and the prospective and retrospective memory questionnaire (PRMQ). Eight cases and four controls also underwent ¹H cerebral magnetic resonance spectroscopy (¹H-MRS) scanning measuring basal ganglia (BG) metabolites. Cases and controls were compared.

Results:

Group 1 mean (SD) CD4 count; 444 (319) cells/μl, plasma HIV viral load?P>0.27 all observations). PRMQ scores were significantly higher (42 versus 35, P?=?0.02) and MRS BG inflammatory-metabolites (choline- and myo-inositol- to creatine ratios) were significantly greater in Group 1 versus Group 2 (0.83 versus 0.63, P?=?0.02 and 3.43 versus 3.03.P?=?0.09 respectively). No significant association between PRMQ score and MRS metabolites was observed (P?=?0.89).

Conclusion:

Statistically significant differences in cerebral function parameters were observed in PaHIV young adults compared to a well-matched control population. The cognitive deficit observed, in memory, rather than fine motor function, differs from the cerebral impairment often reported in HIV-infected adults.     

Human metapneumovirus-associated severe acute respiratory illness hospitalisation in HIV-infected and HIV-uninfected South African children and adults

BackgroundData on human metapneumovirus (HMPV)-associated severe acute respiratory illness (SARI) are limited in settings with high human immunodeficiency virus (HIV) infection prevalence.ObjectivesTo describe clinical characteristics and seasonality (all sites), and incidence (Soweto only) of HMPV-associated SARI among children and adults.Study designActive, prospective, hospital-based, sentinel surveillance for patients hospitalised with SARI was conducted at four sites in South Africa from February 2009–December 2013. Upper respiratory tract samples were tested by multiplex real-time polymerase chain reaction assays for HMPV and other respiratory viruses. Incidence of hospitalisation, stratified by age and HIV-infection status, was calculated for one hospital with population denominators.ResultsHMPV was identified in 4.1% of patients enrolled, including 5.6% (593/10503) in children and 1.7% in adults (≥18 years; 119/6934). The majority of adults (84.0%) had an underlying medical condition, including HIV infection in 87/110 (79.1%). HMPV detection occurred perennially with periods of increased detection, which varied from year to year. The incidence of HMPV-associated hospitalisation in Soweto was highest in infants (653.3 per 100,000 person years; 95% confidence interval (CI) 602.2–707.6). The incidence was higher in HIV-infected persons compared to HIV-uninfected persons in age-groups 5–17 years (RR 6.0; 1.1–20.4), 18−44 years (RR 67.6; 38.0–132.6) and 45–64 years (RR 5.3; 3.4–8.3), while not differing in other age-groups.ConclusionsThe burden of HMPV-associated SARI hospitalisation among adults occurred predominantly in HIV-infected persons. Among children, infants were at highest risk, with similar burden of hospitalisation in HIV-infected and HIV-uninfected children.     

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults

OBJECTIVE:

The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years).

METHODS:

The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm²). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m²), waist-hip ratio and the support base (cm²). Also, a postural balance test was performed using posturography variables with open and closed eyes.

RESULTS:

The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area.

CONCLUSION:

Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females.     

Body composition changes during lactation in HIV-infected and HIV-uninfected South African women

BACKGROUND: The nutritional consequences of HIV infection in lactating women are unknown. OBJECTIVE: To measure the body composition of South African lactating women in relation to HIV status. METHODS: Fat-free mass (FFM) and fat mass (FM) using bioimpedance spectrometry (BIS) and anthropometric measurements were obtained at 8 and 24 weeks postpartum in 92 HIV-infected (HIVpos) and 50 HIV-uninfected (HIVneg) lactating mothers. RESULTS: At 8 weeks, HIVpos and HIVneg mothers were not significantly different in height (159.7 vs. 158.9 cm), weight (62.7 vs. 63.9 kg), body mass index (BMI; 24.6 vs. 25.3 kg/m), FFM (40.7 vs. 42.8 kg), or FM (21.6 vs. 22.0 kg), respectively. In HIVpos women, the median CD4 count was 621 (range: 101-1585) cells/muL; 95% had CD4 counts >200 cells/muL. Between 8 and 24 weeks, HIVpos mothers had a mean weight loss of 1.4 kg in contrast to a 0.4-kg weight gain in HIVneg mothers (P < 0.01). There were no significant group differences with regard to change in FFM (0.3 vs. 0.1 kg; P = 0.9) and FM (-1.5 vs. -0.3 kg; P = 0.2). CONCLUSION: HIVpos South African breast-feeding mothers without severe immune suppression lost weight and subcutaneous fat between 8 and 24 weeks postpartum, whereas HIVneg mothers gained weight. FFM was maintained postpartum in HIVpos and HIVneg mothers.     

Relation of body composition to body mass index in HIV-infected patients with metabolic abnormalities

OBJECTIVE: To determine visceral adiposity (VAT), subcutaneous adiposity (SAT), and regional body adipose differences between HIV-infected and non-HIV-infected subjects in relation to body mass index (BMI) and World Health Organization BMI categories. DESIGN, SETTING, AND PARTICIPANTS: Analyses were conducted of 306 HIV-infected and 107 community-derived HIV-negative subjects evaluated for metabolic studies between 1999 and 2006. Analyses were stratified by gender. Additional analyses were performed stratifying subjects by metabolic syndrome status. RESULTS: HIV-infected men and women demonstrated decreased total extremity fat by 1.1 kg and 0.85 kg, respectively, relative to non-HIV-infected control subjects. VAT was increased among HIV-infected men and women in the normal (18.5 to 24.9 kg/m2) and overweight (25.0 to 29.9 kg/m2) categories relative to control subjects but not among those in the obese category (> or =30.0 kg/m2). In contrast, abdominal SAT was reduced among HIV-infected men in the normal and overweight categories but was similar among HIV-infected women and control subjects in these categories. Abdominal SAT was increased among HIV-infected women in the obese category relative to control subjects. Similar results were obtained limiting the analysis to HIV-infected (n = 204) and control subjects (n = 89) without the metabolic syndrome. CONCLUSIONS: Peripheral lipoatrophy is a consistent finding among HIV-infected men and women with metabolic abnormalities. Relative increases in VAT are most pronounced among male and female HIV-infected subjects in the normal weight and overweight categories. Gender differences in abdominal SAT accumulation are observed, with preservation of SAT among HIV-infected women relative to control subjects.     

Differential relationships between transcallosal structural and functional connectivity in young and older adults

Numerous studies have identified age differences in brain structure and function that correlate with declines in motor performance. While these investigations have typically focused on activity in isolated regions of the brain, resting state functional connectivity magnetic resonance imaging (MRI) and diffusion tensor imaging allow for more integrative assessments of spatially disparate neural networks. The novel contribution of the current study is to combine both resting state functional connectivity and diffusion tensor imaging to examine motor corticocortical circuits in young and older adults. We find that relatively greater functional connectivity between the primary motor cortices was strongly associated with decreased structural connectivity and poorer motor performance solely in older adults. We suggest that greater functional connectivity in older adults may be reflective of a release from the normally predominantly inhibitory interhemispheric communication associated with the primary motor cortices.     

A relationship between bioelectrical impedance and total body water in young adults

Total body water was measured using the stable isotope H2(18)O in 14 young adults. Body resistance was assessed using a tetrapolar technique using a Holtain body-composition analyzer. Total body water was highly correlated (r = 0.96; p less than 0.001) with height2/resistance. The inclusion of body weight in the prediction equation reduced the standard error of estimate from 1.9 to 1.51. Bioelectrical resistance can be used to assess other body-composition parameters such as fat-free mass and fat mass, but this use involves a number of assumptions which may confound the relationship. We suggest that the measurement of bioelectrical impedance may, however, have a role in the estimation of total body water.     

Genetic linkage and imprinting effects on body mass index in children and young adults

Body mass index (BMI) is used as a measure of fatness. Here we performed a genome-wide scan for genes related to BMI, while allowing for the possible effects of imprinting. We applied a sib pair linkage analysis to a sample of primarily children and young adults by using the Haseman-Elston method, which we modified to model the separate effects of paternally and maternally derived genetic factors. After stratification of sib pairs according to age, a number of regions showing linkage with BMI were identified. Most linkage and imprinting effects were found in children 5-11 years of age. Strongest evidences for linkage in children were found on chromosome 20 at 20p11.2-pter near the marker D20S851 (LOD(Total)=4.08, P=0.000046) and near the marker D20S482 (LOD(Total) =3.55, P=0.00016), and Chromosome 16 at 16p13 near the marker ATA41E04 (LOD(Total) =3.12, P=0.00025), and those loci did not show significant evidence for imprinting. Six regions showing evidence of imprinting were 3p23-p24 (paternal expression), 4q31.1-q32 (maternal expression), 10p14-q11 (paternal expression), and 12p12-pter (paternal expression) in children, and 4q31-qter (paternal expression) and 8p (paternal expression) in adults.     

Relationship between body composition and bone mineral content in young and elderly women

PRIMARY OBJECTIVE: To study the relationship between bone mineral content (BMC), lean tissue mass (LTM) and fat mass (FM) in a large sample of young and elderly women. RESEARCH DESIGN: Cross-sectional. METHODS AND PROCEDURES: BMC, LTM and FM were measured by dual-energy X-ray absorptiometry in 2009 free-dwelling Caucasian women aged 63 +/- 7 years (mean +/- SD; range: 37-88 years). The majority of women were postmenopausal (96%). RESULTS: LTM explained 13% more variance of BMC than FM (R(2)(adj) = 0.39 vs 0.26, p < 0.0001) but weight (Wt) explained 5% more variance of BMC than LTM (R(2)(adj) = 0.44, p < 0.0001). The prediction of BMC obtained from LTM and FM (R(2)(adj)= 0.46, p < 0.0001) was only slightly better than that obtained from Wt. After the effects of age, Wt and height (Ht) on BMC were taken into account by multiple regression, the contribution of LTM and FM to BMC was just one-fifth of that of Wt (R(2)(adj) for full models < or =0.56, p < 0.0001). After a further correction for bone area (BA), the contribution of LTM and FM to BMC was just one-tenth of that of BA and not different from that of Wt and Ht on practical grounds (R(2)(adj) for full models = 0.84, p < 0.0001). Thus, after inter-individual differences in age, Wt, Ht (and bone size) are taken into account, the relationship between body composition and BMC is substantially weakened. CONCLUSIONS: In Caucasian women, (1) LTM is a stronger predictor of BMC than FM, but (2) Wt is a better predictor of BMC than body composition for practical purposes, and (3) Wt and body composition are not able to explain more than 46% of BMC variance.     

Relationship between body composition and bone mineral content in young and elderly women

Primary objective : To study the relationship between bone mineral content (BMC), lean tissue mass (LTM) and fat mass (FM) in a large sample of young and elderly women. Research design : Cross-sectional. Methods and procedures : BMC, LTM and FM were measured by dual-energy X-ray absorptiometry in 2009 free-dwelling Caucasian women aged 63 &#45 7 years (mean &#45 SD; range: 37-88 years). The majority of women were postmenopausal (96%). Results : LTM explained 13% more variance of BMC than FM ( R 2 adj = 0.39 vs 0.26, p < 0.0001) but weight (Wt) explained 5% more variance of BMC than LTM ( R 2 adj = 0.44, p < 0.0001). The prediction of BMC obtained from LTM and FM ( R 2 adj = 0.46, p < 0.0001) was only slightly better than that obtained from Wt. After the effects of age, Wt and height (Ht) on BMC were taken into account by multiple regression, the contribution of LTM and FM to BMC was just one-fifth of that of Wt ( R 2 adj for full models &#114 0.56, p < 0.0001). After a further correction for bone area (BA), the contribution of LTM and FM to BMC was just one-tenth of that of BA and not different from that of Wt and Ht on practical grounds ( R 2 adj for full models = 0.84, p < 0.0001). Thus, after inter-individual differences in age, Wt, Ht (and bone size) are taken into account, the relationship between body composition and BMC is substantially weakened. Conclusions : In Caucasian women, (1) LTM is a stronger predictor of BMC than FM, but (2) Wt is a better predictor of BMC than body composition for practical purposes, and (3) Wt and body composition are not able to explain more than 46% of BMC variance.     

Water turnover in children and young adults

Water homeostasis is essential for life and optimal function and considerable interest surrounds the issue of recommendations for water consumption in healthy individuals. Objective data on water turnover in free-living individuals are limited, however. The aim of the present work was to measure water turnover in children and young adults using isotopically labeled water to provide objective data on magnitude and variability in relation to body weight, fat-free mass and physical activity level. Water turnover was measured by deuterated water dilution in 91 healthy children (40 boys, 51 girls; age 5–14 years) and 109 healthy young adults (80 women, 29 men; age 18–27 years) with a wide range of body mass index (13.3–51.8 kg/m²) and percent body fat (6.1–59.3%). Total energy expenditure (TEE) and resting metabolic rate were measured by the doubly labeled water technique and indirect calorimetry, respectively. Water turnover was 1.77 ± 0.57 (SD), 1.79 ± 0.44, 2.85 ± 0.82, and 3.90 ± 0.81 L/day in girls, boys, women, and men, respectively. Water turnover indexed to body surface area did not differ significantly between girls and women but was higher in men than boys. Water turnover indexed to TEE was 0.8 mL/kcal in girls and boys and 1.0 mL/kcal in women and men. This study provides objective data on water turnover for children and young adults in a temperate climate and shows that anthropometric parameters can account for the variation between girls, boys and women but not between these groups and the more active men.     

The use of body mass index to predict body composition in children

Background : Simple anthropometric indices of body composition have particular appeal for use in children, and as such body mass index (BMI) has been used to predict percentage body fat in a number of studies. Aim : To evaluate the relationship between BMI and percentage body fat (%body fat) and a proposed, more appropriate relationship between BMI and fat mass/height 2 in a cohort of young children. Subjects and methods : Cross-sectional study of 109 children aged between 6 and 10 years residing in either Sydney or Brisbane, Australia. Weight and height were measured using standard methods. Body composition was measured using a stable isotope method to firstly determine total body water and subsequently fat free mass. Results : The correlation between BMI and fat mass/height 2 was markedly greater than that between BMI and percentage body fat. In the entire group of children the R 2 ( &#50 100%) value for the relationship between BMI and fat mass/height 2 was 73.3% compared with 46.5% for the relationship between BMI and percentage body fat. Conclusions : We have shown that the use of BMI to predict fat mass/height 2, and consequently percentage body fat, is superior to the use of BMI to predict percentage body fat based directly upon the R 2 values of the above analysis.     

The use of body mass index to predict body composition in children

BACKGROUND: Simple anthropometric indices of body composition have particular appeal for use in children, and as such body mass index (BMI) has been used to predict percentage body fat in a number of studies. AIM: To evaluate the relationship between BMI and percentage body fat (%body fat) and a proposed, more appropriate relationship between BMI and fat mass/height(2) in a cohort of young children. SUBJECTS AND METHODS: Cross-sectional study of 109 children aged between 6 and 10 years residing in either Sydney or Brisbane, Australia. Weight and height were measured using standard methods. Body composition was measured using a stable isotope method to firstly determine total body water and subsequently fat free mass. RESULTS: The correlation between BMI and fat mass/height(2) was markedly greater than that between BMI and percentage body fat. In the entire group of children the R(2) (x100%) value for the relationship between BMI and fat mass/height(2) was 73.3% compared with 46.5% for the relationship between BMI and percentage body fat. CONCLUSIONS: We have shown that the use of BMI to predict fat mass/height(2), and consequently percentage body fat, is superior to the use of BMI to predict percentage body fat based directly upon the R(2) values of the above analysis.     

Bone mass in normal children and young adults

The growth of bone mass in the radius of children from age 6 on was studied in Indiana and Wisconsin. Growth curves describing change in bone mass, bone width, body height and weight were fitted separately to the data of males and females in the two states. Statistically significant differences between states were found in almost all growth measurements in both sexes. Refined growth curves with standard deviations were generated separately for the two states. When adjusted for age and bone width, Wisconsin subjects always had higher mean bone mass than Indiana subjects. Thus researchers should exercise caution when using published normative values established elsewhere.     

Acute hemorrhagic appendicitis in children and young adults

Summary The study of 1008 appendices with acute appendicitis showed 7.5% of these to be hemorrhagic. These were found primarily in children and adolescents and only rarely in adults. The pathogenesis of hemorrhagic reactions in these appendices is explained on the basis of the delicate stroma and vascular structures in the mucosa and submucosa. These seem to be more susceptible to injury than comparable structures in adults. Cases of hemorrhagic appendicitis are very infrequent when these structures have reached their final development. Follicular hyperplasia, however, occurs more frequently in girls and women.

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Akute hämorrhagische Appendicitis bei Kindern und jungen Erwachsenen

Zusammenfassung Bei Untersuchung von 1008 Wurmfortsätzen mit akuter Appendicitis erwies sie sich in 7,5% als hämorrhagisch. Diese Form der Appendicitis wurde hauptsächlich bei Kindern und Jugendlichen, nur selten bei Erwachsenen gefunden. Die Pathogenese der hämorrhagischen Reaktion wird durch den Umstand erklärt, daß das Stroma und die vasculären Strukturen in Mucosa und Submucosa sehr zart sind; sie scheinen auch mehr empfindlich gegen Schädlichkeiten zu sein als vergleichbare Strukturen bei Erwachsenen. Dem entspricht, daß Fälle von hämorrhagischer Appendicitis seltener waren, wenn diese Strukturen ihren endgültigen Zustand erreicht hatten. Follikelhyperplasie kommt häufiger bei Frauen und Mädchen vor.