Cross-cultural comparison of correlates of quality of life and health status: the Whitehall II Study (UK) and the Western New York Health Study (US)

Measures of quality of life (QoL) have been found to be predictors of mortality and morbidity; however, there is still limited understanding of the multifaceted nature of these measures and of potential correlates. Using two large populations from the UK and US, we aimed to evaluate and compare measured levels of QoL and the key factors correlated with these levels. Participants were 6,472 white subjects (1,829 women) from the Whitehall II Study (mean age 55.8 years) and 3,684 white subjects (1,903 women) from the Western New York Health Study (mean age 58.7 years). QoL was assessed in both using the physical and mental health component summaries of the short form-36 questionnaire (SF-36). Analysis of covariance was used to compare gender-specific mean scores for the two populations across several potential correlates (including socio-demographic, lifestyle and co-morbidity factors). Levels of reported physical QoL tended to be higher in the UK population (51.2 vs. 48.6) while mental QoL was higher in the US group (53.1 vs. 51.1). Age, sleep duration and depressive symptoms were the main factors correlated with both physical and mental QoL in both samples. Increasing age was associated with poorer physical health but higher mental health scores in both populations (P<0.001). Sleep duration below 6 or above 8 h was associated with lower levels of QoL. Depressive symptoms were strongly associated with poorer mental health scores (P<0.001) while higher BMI, lower physical activity levels and presence of cardiovascular disease were associated with poorer physical health in both samples and gender (P<0.05). There were consistent findings for correlates of QoL in this cross-cultural comparison of two populations from the UK and US. Strongest associations were between lifestyle and co-morbidity factors and the physical health component of the SF-36 rather than the mental health component. This is a novel finding which warrants further consideration.     

Recent advances in assisted reproductive technologies

Assisted reproductive technologies (ART) have received considerable attention, both clinically and empirically. Drs. Steptoe and Edwards removed one oocyte surgically from a woman with infertility related to tubal disease. They fertilized this oocyte in vitro and transferred the formed embryo to the woman’s uterus and achieved pregnancy and delivery. The technique of in vitro fertilization (IVF) and embryo transfer (ET) quickly became widely utilized for other causes of infertility as well as for tubal disease. In the last 5 years there has been a number of new developments that are reviewed in this article. The most important and now widely practiced technology has been direct intracytoplasmic injection (ICSI) of the husband’s sperm into the wife’s oocyte. This was developed for treatment of infertility related to low sperm count. Subsequently it was shown that sperm can be aspirated from epididymis or found in testicular biopsy in obstructive azoospermia. Another promising development is in vitro maturation (IVM) of immature oocytes. This has the potential of avoiding ovarian hyperstimulation, which can be uncomfortable and occasionally dangerous. Some oocytes are unable to fertilize and/or develop into normal embryos. It may be possible that the problem is with the machinery of cytoplasm of the oocyte. Therefore cytoplasmic transfer from a normal oocyte to an abnormal oocyte may overcome the problem. Infertile couples may be faced with many psychological problems that become even more complex with various treatments. Whereas donation of oocytes or embryos can be technically quite simple, there are many psychological issues involved. As can be gathered from aforementioned discussions, the treatments developed for infertility appear to be somewhat illogical and in the style of “shot gun therapy.” In the field of infertility, as in other areas of medicine, it is of paramount importance to know the details of disease mechanisms. This in turn will allow specific and logical treatments to be developed.     

Hypertension, non-insulin-dependent diabetes, and intracellular sodium metabolism

The present study was designed to investigate whether non-insulin-dependent diabetic hypertensive patients exhibit abnormalities in intracellular sodium metabolism similar to those described for essential hypertensive patients. Both normotensive and hypertensive non-insulin-dependent diabetic patients had similar average values of both Na+-Li+ countertransport and Na+-K+ cotransport compared with nondiabetic controls. Within the group of diabetic patients, hypertensive patients did not exhibit any abnormalities in either of the sodium transport pathways studied. The possible implications of these findings are addressed.     

Porcine and human insulin absorption from subcutaneous tissues in normal and insulin-dependent diabetic subjects: a deconvolution-based approach

The mechanisms of sc insulin absorption are not understood, and models for interpreting in vivo data cannot be developed without gross simplification. To overcome this difficulty we developed a new approach which makes use of deconvolution analysis and does not require any model of the sc tissue. In five normal subjects and seven insulin-dependent diabetic (IDDM) patients endogenous insulin secretion was suppressed by means of a hypoglycemic glucose clamp procedure (approximately 2.8 mmol/L) sustained by a continuous insulin infusion (approximately 4 pmol/min.kg). A bolus injection of insulin (5.4 nmol) was administered iv, and plasma insulin concentrations were measured frequently for 2 h to assess iv insulin kinetics. Insulin then was injected sc in the abdominal region, and plasma insulin concentrations were measured for 8 h. Each subject was studied twice, with porcine and semisynthetic human insulin (Actrapid, Novo). The rate of insulin absorption was reconstructed by deconvolution from the plasma concentrations and iv insulin kinetic data. Linearity of the iv insulin kinetics, essential for deconvolution analysis, was confirmed by a dose-response study in the range of the measured concentrations (150-1800 pmol/L). In most instances, a two-compartment model was adequate to describe the iv response. The mean plasma insulin clearance rates were 15.5 +/- 1.9 (+/- SD) mL/min.kg (porcine) and 17.2 +/- 6.0 (human) in normal subjects and 20.7 +/- 8.8 (porcine) and 20.9 +/- 9.1 (human) in the IDDM patients. The rate of appearance of human insulin from sc tissue was faster than that of porcine insulin in both normal and IDDM subjects, but no significant differences were found in bioavailability, which was 55 +/- 12% (+/- SD; porcine) and 61 +/- 34% (human) in the normal subjects, and 84 +/- 28% (porcine) and 86 +/- 23% (human) in the IDDM patients. The rate of absorption and bioavailability were higher in the IDDM patients than in the normal subjects, a difference possibly related to increased sc blood flow in the IDDM patients. No differences were found with regard to glucose requirement values, normalized to plasma insulin concentrations, in agreement with the finding that the bioavailability of the two insulin species was similar.     

Relation between lung function and RBC distribution width in a population-based study

STUDY OBJECTIVES: Pulmonary function is dependent not only on smoking, but also on nutritional status. Since an increased RBC distribution width (RDW) has been associated with nutritional deficiencies, we postulated that RDW has an inverse relation to pulmonary function. The purpose of this study was to test this hypothesis. DESIGN AND SETTING: A cross-sectional study was conducted of a random sample of the general population in western New York. PARTICIPANTS: A total of 1,616 subjects of both genders who were aged 35 to 79 years and were free of respiratory disease. INTERVENTIONS: None. MEASUREMENTS: Pulmonary function was assessed from FEV(1), FVC, height, body weight, total pack-years of smoking, smoking status, hemoglobin concentration, and hematologic indexes, eosinophil count, education, and blood levels of retinol, beta-cryptoxanthin, and vitamin E. RESULTS: We found a direct relation between RDW and the number of pack-years of smoking and smoking status, and an inverse relation between FEV(1) and FVC with RDW, even when potentially confounding variables such as smoking were taken into account. When the variability of FEV(1) due to smoking was used for comparison, an additional 27% of that variability in FEV(1) was explained by variations in antioxidant vitamin levels, and another 24% by RDW. CONCLUSIONS: The results confirmed our hypothesis that there is an inverse relation between RDW and pulmonary function, and raise the possibility that RDW may be a biomarker for as-yet unidentified nutrients that affect pulmonary function.     

Pulmonary function is a long-term predictor of mortality in the general population: 29-year follow-up of the Buffalo Health Study

STUDY OBJECTIVES: Results from several studies have described a relationship between pulmonary function and both all-cause and cause-specific mortality. The purpose of this study was to investigate the predictive value of pulmonary function by gender after 29 years of follow-up. DESIGN: Prospective study with 29-year follow-up of the Buffalo Health Study cohort. PARTICIPANTS: Randomly selected sample of 554 men and 641 women, aged 20 to 89 years, from all listed households of the city of Buffalo, NY. MEASUREMENTS AND RESULTS: Baseline measurements were performed in 1960 to 1961. Pulmonary function was assessed based on FEV(1) expressed as the normal percent predicted (FEV(1)%pred). FEV(1)%pred adjusted by age, body mass index, systolic BP, education, and smoking status was inversely related to all-cause mortality in both men and women (p<0.01). A sequential survival analysis in participants who had a survival time of at least 5, 10, 15, 20, and 25 years after enrollment in the study was also performed. Except for men who survived for > 25 years, we observed a statistically significant negative association between FEV(1)%pred and all-cause mortality. FEV(1)%pred was also inversely related to ischemic heart disease (IHD) mortality. When participants were divided into quintiles of FEV(1)%pred, participants in the lowest quintile of FEV(1)%pred experienced significantly higher all-cause mortality compared with participants in the highest quintile of FEV(1)%pred. For the entire follow-up period, the adjusted hazard ratios for all-cause mortality were 2.24 (95% confidence interval [CI], 1.60 to 3.13) for men and 1. 81 (95% CI, 1.24 to 2.63) for women, respectively. Hazard ratios for death from IHD in the lowest quintile of FEV(1)%pred were 2.11 (95% CI, 1.20 to 3.71) and 1.96 (95% CI, 0.99 to 3.88) for men and women, respectively. CONCLUSIONS: These results suggest that pulmonary function is a long-term predictor for overall survival rates in both genders and could be used as a tool in general health assessment.     

Angioplasty Guided by Intravascular Ultrasound: Meta-Analysis of Randomized Clinical Trials

Background

The impact of intravascular ultrasound (IVUS) use on stenting has shown inconclusive results.

Objective

Systematic review and meta-analysis of the impact of IVUS on stenting regarding the clinical and angiographic evolution.

Methods

A search was performed in Medline/Pubmed, CENTRAL, Embase, Lilacs, Scopus and Web of Science databases. It included randomized clinical trials (RCTs) that evaluated the implantation of stents guided by IVUS, compared with those using angiography alone (ANGIO). The minimum follow-up duration was six months and the following outcomes were assessed: thrombosis, mortality, myocardial infarction, percutaneous and surgical revascularization, major adverse cardiovascular events (MACE) and restenosis. The binary outcomes were presented considering the number of events in each group; the estimates were generated by a random effects model, considering Mantel-Haenszel statistics as weighting agent and magnitude of effect for the relative risk (RR) with its respective 95% confidence interval (95%CI). Higgins I² test was used to quantify the consistency between the results of each study.

Results

A total of 2,689 articles were evaluated, including 8 RCTs. There was a 27% reduction in angiographic restenosis (RR: 0.73, 95% CI: 0.54-0.97, I² = 51%) and statistically significant reduction in the rates of percutaneous revascularization and overall (RR: 0.88; 95% CI: 0.51 to 1.53, I² = 61%, RR: 0.73, 95% CI: 0.54 to 0.99, I² = 55%), with no statistical difference in surgical revascularization (RR: 0.95, 95% CI: 0.52-1.74, I² = 0%) in favor of IVUS vs. ANGIO. There were no differences regarding the other outcomes in the comparison between the two strategies.

Conclusion

Angioplasty with stenting guided by IVUS decreases the rates of restenosis and revascularization, with no impact on MACE, acute myocardial infarction, mortality or thrombosis outcomes.     

Exercise-induced recurrent myoglobinuria: defective activity of inner carnitine palmitoyltransferase in muscle mitochondria of two patients

In carnitine palmitoyltransferase (CPT) deficiency, it is not known whether the outer (CPT-I) and the inner (CPT-II) mitochondrial activities are equally altered. By two different assays, we found that CPT activity in fresh intact mitochondria of two patients was normal or increased, indicating an active outer CPT. In controls and in one of the two patients, the isotope-exchange assay was also evaluated after disruption of mitochondria by sonication: in controls the activity almost doubled because of the contribution of inner CPT to the assay, but in the patients it did not increase, indicating absence of the CPT-II activity. After further disruption of mitochondria by freezing and all-glass homogenization, CPT activity in patients decreased to 36% and 10% of control. These data suggest CPT deficiency was limited to the inner mitochondrial activity. The alteration could be explained by mutation of the membrane factor that determines in situ differences between CPT-I and II.