Spectral resolution of cardio-circulatory variations in men measured by autorhythmometry over 2 years

An analogue of the periodogram method for unequally spaced data is presented with a view to resolving the frequency structure of the observations. The algorithm is explicitly based on the sequential least squares procedure. In particular, the key concept is that the with-in-plot spectral analysis can be augmented by the between-plot information to make inferences about common characteristics. It is also shown how the between-plot random variations can be incorporated into the multiple harmonic regression model. A detailed spectral analysis investigates the periodic fluctuations in four cardio-circulatory variables, measured by autorhythmometric observation by eight men at rest and extending over a time span of 2 years. The spectral curves show the existence of circadian and circaseptan rhythmicities. The amplitude modulation of the dian rhythm by circaseptan variation is assimilated with the rhythmicity of work during the week. The blood-pressure variables situate their maximum annual peak in the winter period. These quasi-periodic fluctuations appear to be related to the amount of physical activity performed in time by the subjects.     

X chromosome inactivation pattern in elderly women over 70 years of age

In the present study we have analyzed X chromosome inactivation patterns in 40 women aged from 74 to 85 years (mean age 78 years). The control group was 36 women (mean age 30 years). The most common AR-assay was used to determine X-inactivation patterns (the study of methylation patterns of HpaII site in human androgen receptor gene (HUMARA) by quantative PCR). The age dependence of X-inactivation was not observed. We have detected skewed X-inactivation in three women among 40 (7.5%) elderly women comparing to two women among 36 (5.5%) women from control group. The difference was not found to be statistically significant. We made a suggestion that higher incidence of skewed X-inactivation in elderly women revealed by previous studies could occur due to some experimental ambiguities as heterogeneity of the group studied; inclusion of women having relatives with genetic abnormalities associated with skewed X-inactivation patterns; the difference of X chromosome inactivation skewing determination. We conclude that present study does not show X chromosome inactivation to be age dependent.     

MRI as a diagnostic technique in examination of the shoulder joint

The paper presents the results of examination of 95 patients with shoulder joint abnormality to define the capacities of MR imaging in the evaluation of the anatomic structures of this joint. It details the MR anatomic features of the shoulder joint. Some conditions should be adhered to while performing MRI of the joint, namely: to obtain high-quality images by correctly choosing pulse sequences and scanning planes and to know the anatomic variants of the structure of the shoulder joint.     

Activation of shoulder muscles in healthy men and women under isometric conditions

Purpose: Due to the low osseous lead of the shoulder joint a large portion of the shoulder muscles, in addition to executing movements, deals with stabilising tasks. This requires a permanent readjustment of the intermuscular co-ordination of all involved muscles. The aim of the study was to verify the existence of gender dependent differences in intramuscular co-ordination patterns of shoulder muscles.

Method: Fifteen healthy men and nine healthy women, who executed 24 isometric exercises in sagittal, frontal and horizontal planes with a loading of 50% of their individual isometric maximum force, were investigated. In every plane, four angular positions were chosen and both opposite force directions were measured, respectively. SEMG was taken from 13 muscles of the shoulder and the upper arm. Due to inter-individual differences SEMG amplitudes were normalised. Results: Gender specific differences of functional intermuscular co-ordination patterns could be proven systematically. Women showed less activation of muscles acting in the main force direction. In addition, those muscles less necessary for the actual force production were more activated in women than in men.

Conclusions: Functionally comparable shoulder function showed a gender dependency in terms of functional intermuscular co-ordination.     

One- and two-year change in body composition as measured by DXA in a population-based cohort of older men and women.

Changing body composition has been suggested as a pathway to explain age-related functional decline. No data are available on the expected changes in body composition as measured by dual-energy X-ray absorptiometry (DXA) in a population-based cohort of older persons. Body composition data at baseline, 1-yr follow-up, and 2-yr follow-up was measured by DXA in 2,040 well-functioning black and white men and women aged 70-79 yr, participants of the Health, Aging, and Body Composition Study. After 2 yr, a small decline in total body mass was observed (men: -0.3%, women: -0.4%). Among men, fat-free mass and appendicular lean soft tissue mass (ALST) decreased by -1.1 and -0.8%, respectively, which was masked by a simultaneous increase in total fat mass (+2.0%). Among women, a decline in fat-free mass was observed after 2 yr only (-0.6%) with no change in ALST and body fat mass. After 2 yr, the decline in ALST was greater in blacks than whites. Change in total body mass was associated with change in ALST (r = +0.58 to +0.70; P < 0.0001). Among participants who lost total body mass, men lost relatively more ALST than women, and blacks lost relatively more ALST than whites. In conclusion, the mean change in body composition after a 1- to 2-yr follow-up was 1-2% with a high interindividual variability. Loss of ALST was greater in men compared with women, and greater in blacks compared with whites, suggesting that men and blacks may be more prone to muscle loss.     

Testosterone levels and their associations with lifetime number of opposite sex partners and remarriage in a large sample of American elderly men and women

Testosterone (T) has been argued to modulate mating and parenting behavior in many species, including humans. The role of T for these behaviors has been framed as the challenge hypothesis. Following this hypothesis, T should be positively associated with the number of opposite sex partners a male has. Indeed research in humans has shown that T is positively related to the number of opposite sex partners a young man has had. Here we test, in both men and women, whether this relationship extends to the lifetime number of sex partners. We also explored whether or not T was associated with current marital status, partnership status and whether or not the participant remarried. Using a large sample of elderly men and women (each sample n > 700), we show that T is positively and sizably associated with the number of opposite sex partners in men. When controlling for potential confounding variables such as educational attainment, age, BMI, ethnicity, specific use of a medication and time of sampling this effect remained. For women, the relationship between T and number of opposite sex partners was positive but did not prove to be robust. In both men and women there was no evidence for an association between T and current marital status and partnership status (being in a relationship or not). However, remarriage was positively associated with T, but only in males. Results are discussed with reference to the literature on T and sex partners, remarriage and more broadly the challenge hypothesis.     

Change in bone mineral density as a function of age in women and men and association with the use of antiresorptive agents

Background

Measurement of bone mineral density is the most common method of diagnosing and assessing osteoporosis. We sought to estimate the average rate of change in bone mineral density as a function of age among Canadians aged 25–85, stratified by sex and use of antiresorptive agents.

Methods

We examined a longitudinal cohort of 9423 participants. We measured the bone mineral density in the lumbar spine, total hip and femoral neck at baseline in 1995–1997, and at 3-year (participants aged 40–60 years only) and 5-year follow-up visits. We used the measurements to compute individual rates of change.

Results

Bone loss in all 3 skeletal sites began among women at age 40–44. Bone loss was particularly rapid in the total hip and was greatest among women aged 50–54 who were transitioning from premenopause to postmenopause, with a change from baseline of –6.8% (95% confidence interval [CI] –7.5% to –4.9%) over 5 years. The rate of decline, particularly in the total hip, increased again among women older than 70 years. Bone loss in all 3 skeletal sites began at an earlier age (25–39) among men than among women. The rate of decline of bone density in the total hip was nearly constant among men 35 and older and then increased among men older than 65. Use of antiresorptive agents was associated with attenuated bone loss in both sexes among participants aged 50–79.

Interpretation

The period of accelerated loss of bone mineral density in the hip bones occurring among women and men older than 65 may be an important contributor to the increased incidence of hip fracture among patients in that age group. The extent of bone loss that we observed in both sexes indicates that, in the absence of additional risk factors or therapy, repeat testing of bone mineral density to diagnose osteoporosis could be delayed to every 5 years.Low bone mineral density is one of the most important risk factors for fracture.^1,2,3–7 Treatment with antiresorptive agents has been widely used for several decades, and the results of randomized controlled trials have shown that at least part of their efficacy is associated with their capacity to increase or stabilize bone density.⁴ Although clinical guidelines recommend measurement of bone density, among other important risk factors, when assessing a patient''s risk for fracture,^3,8,9 there is no international consensus on the optimal age at which to begin measurement, or on the frequency of measurement.¹⁰ The Canadian guidelines recommend it for patients aged 65 and older, even in the absence of risk factors or treatment, and suggest a frequency of every 2–3 years.⁸ Furthermore, it has been suggested that the rate of decline rather than a single measurement of bone density may better identify patients with an elevated risk for fracture.¹¹ Consequently, determining changes in bone density over time may provide clues on the pathophysiology of fractures and provide more accurate estimates of the optimal timing for repeat measurement.Previous studies of change in bone mineral density as a function of age have had a number of limitations. Many were cross-sectional; had small samples, limited age ranges or differing inclusion and exclusion criteria; and most excluded men.^12–20 The third National Health and Nutrition Examination Survey,²¹ a large cross-sectional study based in the United States included women and men aged 20 years and older but excluded only those who were pregnant or who had a fracture in both hips. It reported that, based on a single measurement of bone density in the hip, age-dependent bone loss in the hips begins early (20–40 years) and continues in both sexes throughout life. Cross-sectional data from the ongoing Canadian Multicentre Osteoporosis Study suggested that, although this finding may hold true for the femoral neck, which consists of both cortical and trabecular bone, it is not true for the largely trabecular lumbar spine.²² Furthermore, the use of cross-sectional data to estimate changes over time has fundamental limitations: the effect of age cannot be separated from the effect of birth cohort and survivorship, and estimates are based on between-group differences rather than changes in an individual participant.The use of longitudinal data would allow examination of the rate of change of bone mineral density over time with and without antiresorptive therapy. We sought to assess the average rate of change in bone density as a function of age among Canadians aged 25–85, stratified by sex and use of antiresorptive agents.     

Serum manganese concentrations in a representative sample of the Canarian population

Serum manganese (Mn) concentrations of 368 individuals 6–75 yr of age (179 males and 189 females) living in the Canary Islands were determined by graphite furnace atomic absorption spectrometry. The mean manganese concentration was 1.06 ± 0.62 μg/L, ranging between 0.19 and 3.33 μg/L. Most of the analyzed samples (63.3% of the samples) fall within the reference interval (0.54–1.76 μg/L) for apparently healthy people. Individuals from Fuerteventura presented with mean Mn concentrations significantly higher than individuals from the rest of the islands. This could be attributed to differences in the Mn content of soil and/or differences in dietary habits of the population. Serum Mn concentration did not vary with gender, and individuals younger than 18 yr old had the highest mean Mn concentration, compared to the rest of the age groups considered. No relation to socioeconomic status, educational level, and tobacco or alcohol consumption was found. However, the serum Mn concentration tended to decrease when increasing the consumption of wine or beer. Sportsmen presented significantly higher serum Mn concentrations than the rest.     

Education and risk of cancer in a large cohort of men and women in the United States

Background

Education inequalities in cancer incidence have long been noted. It is not clear, however, whether such inequalities persist in the United States, especially for less common malignancies and after adjustment for individual risk factors.

Methodology/Principal Findings

Within the NIH–AARP Diet and Health Study, we examined the association between education and the risk of developing cancers in a prospective cohort of 498 455 participants who were 50–71 year old and without cancer at enrollment in 1995/96. During a maximum 8.2 years of follow–up we identified 40 443 cancers in men and 18 367 in women. In age-adjusted models, the least educated men (Conclusions/SignificanceWe found a higher risk of malignant disease, particularly smoking– related cancers, among those in the lowest educational attainment category. Only some of the educational gradient is attributable to smoking. The persistence of substantial education inequalities in cancer incidence poses a challenge for etiologic research and public health policy.     

The influence of age,sex, population group,and dentition on the mandibular angle as measured on a South African sample

The mandibular angle is measured in physical anthropological assessments of human remains to possibly assist with the determination of sex and population affinity. The purpose of this investigation was to establish how the mandibular angle changes with age and loss of teeth among the sexes in South African population groups. The angles of 653 dried adult mandibles from the Pretoria Bone Collection were measured with a mandibulometer. Males and females of both South African whites and blacks were included. To compensate for imbalances in numbers among subgroups, type IV ANOVA testing was applied. No association was found between age and angle within either of the populations, within sexes, or within dentition groups. The angle was the most obtuse in individuals without molars and with an uneven distribution of molars, and most acute in the group with an even distribution of molars on both sides. Statistically significant differences (P < 0.001) were found in the angle between the two population groups and sexes in the overall sample as well as in the subgroup with absent molar teeth (P = 0.003 for sex, males more acute angle, and P = 0.001 for population group, blacks more acute angle), although a very large overlap existed. No significant differences could be demonstrated between the sexes or populations within the subgroups with molars. We concluded that the loss of molars, especially if complete or uneven, has a considerable effect on the mandibular angle. In the assessment of human remains, the mandibular angle is not very usable in determining sex. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

Amalgam fillings and cognitive abilities in a representative sample of the elderly population

Objectives: The ongoing controversial discussion about a possible negative effect of amalgam fillings on the cognitive abilities and the pathogenesis dementia was the objective of the present study. Sample: A total of 300 patients aged from 70 to 103 years were selected from the multidisciplinary ‘Berlin Aging Study’ (Base). The sample was heterogeneous concerning lifestyle, education and social prestige. According to their dental state subjects were allocated into three groups: edentate ≥20 years (I) and residual teeth without (II) or with (III) amalgam restorations. All groups were matched for age and gender. Design: Dental examinations and various psychiatric as well as psychological assessments were carried out by professionals within the protocol of the BASE. Tests were chosen to reveal the presence and degree of dementia and assess cognitive abilities such as ‘perceptual speed’, ‘reasoning’, ‘memory’, ‘fluency’ and ‘knowledge’. Results: The present findings negate a correlation between the dental state and the pathogenesis of dementia and the physiological age‐related decline in cognitive abilities. Thus the presence of amalgam fillings did neither correlate to a demented mental condition nor an impaired cognitive performance.