Dimitrios Vagenas

Gender Differences in Social Network Size and Satisfaction in Adults in Their 70s

Strong social support is associated with lower mortality and morbidity and better self-rated health in later life. The aim of this study was to compare social network size and satisfaction in men (N = 2589) and women (n = 3152), aged 72—78 years. Women reported significantly larger networks (Difference 1.36, 95% CI 0.89, 1.83) than men. However, being separated, divorced or single had a significantly greater impact on men’s social networks (Difference 0.92, 95% CI 0.17, 1.68). Poor mental health and sensory impairments were associated with smaller networks and lower satisfaction with support for both men and women.

Repeatability of Measuring Corneal Subbasal Nerve Fiber Length in Individuals With Type 2 Diabetes

Purpose: To analyze the repeatability of measuring nerve fiber length (NFL) from images of the human corneal subbasal nerve plexus using semiautomated software. Methods: Images were captured from the corneas of 50 subjects with type 2 diabetes mellitus who showed varying severity of neuropathy, using the Heidelberg Retina Tomograph 3 with Rostock Corneal Module. Semiautomated nerve analysis software was independently used by two observers to determine NFL from images of the subbasal nerve plexus. This procedure was undertaken on two occasions, 3 days apart. Results: The intraclass correlation coefficient values were 0.95 (95% confidence intervals: 0.92–0.97) for individual subjects and 0.95 (95% confidence intervals: 0.74–1.00) for observer. Bland-Altman plots of the NFL values indicated a reduced spread of data with lower NFL values. The overall spread of data was less for (a) the observer who was more experienced at analyzing nerve fiber images and (b) the second measurement occasion. Conclusions: Semiautomated measurement of NFL in the subbasal nerve fiber layer is highly repeatable. Repeatability can be enhanced by using more experienced observers. It may be possible to markedly improve repeatability when measuring this anatomic structure using fully automated image analysis software.

Genetic control of resistance to gastro-intestinal parasites in crossbred cashmere-producing goats: responses to selection, genetic parameters and relationships with production traits

This paper investigates the genetic control of the resistance of goats to nematode parasites, and relationships between resistance and production traits. The data set comprised faecal egg counts (FECs) measured on 830 naturally challenged (predominant species Teladorsagia circumcincta ), crossbred cashmere-producing goats over 5 years (1993-1997) and production traits (fibre traits and live weight) on 3100 goats from the same population in Scotland, over 11 years (1987-1997). Egg counts comprised repeated measurements (4 to 11) taken at 12 to 18 months of age and production traits, i.e. live weight and fibre traits, were measured at approximately 5 months of age. The goats for which FECs were available were subdivided into a line selected for decreased FECs, using the geometric mean FEC across the measurement period and goats not selected on the basis of FECs, acting as controls. The selected line had significantly lower FECs, compared with the control, in 4 out of 5 years (back transformed average proportional difference of 0·23). The heritability of a single FEC measurement (after cubic root transformation) was 0·17 and the heritability of the mean FEC was 0·32. The heritabilities of the fibre traits were moderate to high with the majority in excess of 0·5. The heritability of live weight was 0·22. Genetic correlations between FECs and production traits were slightly positive but not significantly different from zero. Phenotypic and environmental correlations were very close to zero with the environmental correlations always being negative. It is concluded that selection for reduced FEC is possible for goats. Benefits of such selection will be seen when animals are kept for more than 1 year of productive life.

Corneal sensitivity as an ophthalmic marker of diabetic neuropathy.

Purpose. The objective of this study was to explore the discriminative capacity of non-contact corneal esthesiometry (NCCE) when compared with the neuropathy disability score (NDS) score—a validated, standard method of diagnosing clinically significant diabetic neuropathy. Methods. Eighty-one participants with type 2 diabetes, no history of ocular disease, trauma, or surgery and no history of systemic disease that may affect the cornea were enrolled. Participants were ineligible if there was history of neuropathy due to non-diabetic cause or current diabetic foot ulcer or infection. Corneal sensitivity threshold was measured on the eye of dominant hand side at a distance of 10 mm from the center of the cornea using a stimulus duration of 0.9 s. The NDS was measured producing a score ranging from 0 to 10. To determine the optimal cutoff point of corneal sensitivity that identified the presence of neuropathy (diagnosed by NDS), the Youden index and “closest-to-(0,1)” criteria were used. Results. The receiver-operator characteristic curve for NCCE for the presence of neuropathy (NDS ≥3) had an area under the curve of 0.73 (p = 0.001) and, for the presence of moderate neuropathy (NDS ≥6), area of 0.71 (p = 0.003). By using the Youden index, for an NDS ≥3, the sensitivity of NCCE was 70% and specificity was 75%, and a corneal sensitivity threshold of 0.66 mbar or higher indicated the presence of neuropathy. When NDS ≥6 (indicating risk of foot ulceration) was applied, the sensitivity was 52% with a specificity of 85%. Conclusions. NCCE is a sensitive test for the diagnosis of minimal and more advanced diabetic neuropathy and may serve as a useful surrogate marker for diabetic and perhaps other neuropathies.

Weight and weight change following breast cancer: evidence from a prospective, population-based, breast cancer cohort study

BackgroundWhile weight gain following breast cancer is considered common, results supporting these findings are dated. This work describes changes in body weight following breast cancer over 72 months, compares weight with normative data and explores whether weight changes over time are associated with personal, diagnostic, treatment or behavioral characteristics.MethodsA population-based sample of 287 Australian women diagnosed with early-stage invasive breast cancer was assessed prospectively at six, 12, 18 and 72 months post-surgery. Weight was clinically measured and linear mixed models were used to explore associations between weight and participant characteristics (collected via self-administered questionnaire). Those with BMI changes of one or more units were considered to have experienced clinically significant changes in weight.ResultsMore than half (57%) of participants were overweight or obese at 6 months post-surgery, and by 72 months post-surgery 68% of women were overweight or obese. Among those who gained more weight than age-matched norms, clinically significant weight gain between 6 and 18 months and 6 and 72 months post-surgery was observed in 24% and 39% of participants, respectively (median [range] weight gain: 3.9 kg [2.0-11.3 kg] and 5.2 kg [0.6-28.7], respectively). Clinically-significant weight losses were observed in up to 24% of the sample (median [range] weight loss between 6 and 72 months post-surgery: −6.4 kg [−1.9--24.6 kg]). More extensive lymph node removal, being treated on the non-dominant side, receiving radiation therapy and lower physical activity levels at 6 months was associated with higher body weights post-breast cancer (group differences >3 kg; all p < 0.05).ConclusionsWhile average weight gain among breast cancer survivors in the long-term is small, subgroups of women experience greater gains linked with adverse health and above that experienced by age-matched counterparts. Weight change post-breast cancer is a contemporary public health issue and the integration of healthy weight education and support into standard breast cancer care has potential to significantly improve the length and quality of cancer survivorship.

Natural history of corneal nerve morphology in mild neuropathy associated with type 1 diabetes: development of a potential measure of diabetic peripheral neuropathy

PURPOSE To investigate longitudinal changes of subbasal nerve plexus (SNP) morphology and its relationship with conventional measures of neuropathy in individuals with diabetes. METHODS A cohort of 147 individuals with type 1 diabetes and 60 age-balanced controls underwent detailed assessment of clinical and metabolic factors, neurologic deficits, quantitative sensory testing, nerve conduction studies, and corneal confocal microscopy at baseline and four subsequent annual visits. The SNP parameters included corneal nerve fiber density (CNFD), branch density (CNBD), and fiber length (CNFL), and were quantified using a fully automated algorithm. Linear mixed models were fitted to examine the changes in corneal nerve parameters over time. RESULTS At baseline, 27% of the participants had mild diabetic neuropathy. All SNP parameters were significantly lower in the neuropathy group compared with controls (P < 0.05). Overall, 89% of participants examined at baseline also completed the final visit. There was no clinically significant change to health and metabolic parameters and neuropathy measures from baseline to the final visit. Linear mixed model revealed a significant linear decline of CNFD (annual change rate, -0.9 nerve/mm(2), P = 0.01) in the neuropathy group compared with controls, which was associated with age (β = -0.06, P = 0.04) and duration of diabetes (β = -0.08, P = 0.03). In the neuropathy group, absolute changes of CNBD and CNFL showed moderate correlations with peroneal conduction velocity and cold sensation threshold, respectively (r, 0.38 and 0.40, P < 0.05). CONCLUSIONS This study demonstrates dynamic small fiber damage at the SNP, thus providing justification for our ongoing efforts to establish corneal nerve morphology as an appropriate adjunct to conventional measures of diabetic peripheral neuropathy.

Why are death rates higher in rural areas? Evidence from the Australian Longitudinal Study on Women's Health.

Objective: Death rates in Australia are higher in rural than urban areas. Our objective is to examine causes of death of urban and rural women to gain insight into potential explanations for differences in mortality.

Is there a bidirectional relationship between maternal well-being and child behavior problems in autism spectrum disorders? Longitudinal analysis of a population-defined sample of young children.

The aim of this study was to examine whether the relationship between maternal psychological well‐being and behavior problems in children with an autism spectrum disorder (ASD) is bidirectional. Data were available at 9 months, 3 years, and 5 years old for 132 children with ASD, identified from a population‐representative sample of UK children. Three‐wave cross‐lagged models examined reciprocal effects between child behavior and maternal well‐being (psychological distress, physical health functioning, and life satisfaction). Results indicated that the relationships between maternal well‐being and child problem behaviors were not bidirectional. Specifically, findings suggested that while early behavior problems are not a risk factor for later maternal well‐being, maternal psychological distress, physical health limitations, and lower life satisfaction are risk factors for later child behavior problems. Autism Res 2013, 6: 201–211.

Morphometric stability of the corneal subbasal nerve plexus in healthy individuals: a 3-year longitudinal study using corneal confocal microscopy.

PURPOSE We examined the age-dependent alterations and longitudinal course of subbasal nerve plexus (SNP) morphology in healthy individuals. METHODS Laser-scanning corneal confocal microscopy, ocular screening, and health and metabolic assessment were performed on 64 healthy participants at baseline and at 12-month intervals for 3 years. At each annual visit, eight central corneal images of the SNP were selected and analyzed using a fully-automated analysis system to quantify corneal nerve fiber length (CNFL). Two linear mixed model approaches were fitted to examine the relationship between age and CNFL, and the longitudinal changes of CNFL over three years. RESULTS At baseline, mean age was 51.9 ± 14.7 years. The cohort was sex balanced (χ(2) = 0.56, P = 0.45). Age (t = 1.6, P = 0.12) and CNFL (t = -0.50, P = 0.62) did not differ between sexes. A total of 52 participants completed the 36-month visit and 49 participants completed all visits. Age had a significant effect on CNFL (F[1,33] = 5.67, P = 0.02) with a linear decrease of 0.05 mm/mm(2) in CNFL per one year increase in age. No significant change in CNFL was observed over the 36-month period (F[1,55] = 0.69, P = 0.41). CONCLUSIONS The CNFL showed a stable course over a 36-month period in healthy individuals, although there was a slight linear reduction in CNFL with age. The findings of this study have implications for understanding the time-course of the effect of pathology and surgical or therapeutic interventions on the morphology of the SNP, and serves to confirm the suitability of CNFL as a screening/monitoring marker for peripheral neuropathies.

Women who smoke like men die like men who smoke: findings from two Australian cohort studies

Background There is controversy about whether men and women with similar smoking histories have similar incidence and mortality rates from smoking related diseases. Objective To compare mortality rates from all causes of death and various smoking related causes for men and women smokers categorised by numbers of cigarettes smoked and for ex-smokers by time since quitting. Methods This was a 10-year follow-up study with deaths identified from the National Death Index. The setting was two cohort studies in Australia established in 1996. Participants were: men (n=12 154) and women (n=11 707) aged (mean (SD)) 72.1 (4.4) and 72.5 (1.5) years, respectively, when recruited. The main outcome measure was HRs for men and women separately and RRs calculated from combined analyses using proportional hazards models (for deaths from all causes) and competing risks proportional hazards models (for specific causes). Results HRs for deaths from all causes for men (n=3549 deaths) and women (n=2665 deaths) among smokers increased with amount smoked and for ex-smokers decreased with time since quitting. Similar effects were found for various groups of smoking-related conditions with the dose-response effects largest for lung cancer and chronic obstructive pulmonary disease. The ratios of HRs for women relative to men were near unity and the 95% CIs included unity for almost all comparisons. Conclusions The data provide strong evidence that men and women with similar patterns of smoking experience similar rates of death due to smoking.