Association of body mass index with the development of methacholine airway hyperresponsiveness in men: the Normative Aging Study

Background: The rising prevalence of asthma in developed nations may be associated with the rising prevalence of obesity in these same nations. The relationship between body mass index (BMI) and the development of an objective marker for asthma, methacholine airway hyperresponsiveness (AHR), was investigated in adult men. Methods: Sixty one men who had no AHR at initial methacholine challenge testing but who developed AHR about 4 years later and 244 matched controls participated in the study. The effects of initial BMI and change in BMI on development of AHR were examined in conditional logistic regression models. Results: Initial BMI was found to have a non-linear relationship with development of AHR. Compared with men with initial BMI in the middle quintile, men with BMI in the lowest quintile (BMI=19.8–24.3 kg/m(2)) and those with BMI in the highest quintile (BMI >29.4 kg/m(2)) were more likely to develop AHR: OR=7.0 (95% CI 1.8 to 27.7) and OR=10.0 (95% CI 2.6 to 37.9), respectively. These results remained significant after controlling for age, smoking, IgE level, and initial FEV(1). In addition, there was a positive linear relationship between change in BMI over the period of observation and the subsequent development of AHR. Conclusions: In this cohort of adult men, both a low BMI and a high BMI were associated with the development of AHR. For men with a low initial BMI the increased risk for development of AHR appears to be partly mediated by a gain in weight. The effect of BMI on AHR may suggest mechanisms in the observed associations between obesity and asthma

Randomised controlled trial of an automated, interactive telephone intervention (TLC Diabetes) to improve type 2 diabetes management: baseline findings and six-month outcomes

Background: Effective self-management of diabetes is essential for the reduction of diabetes-related complications, as global rates of diabetes escalate. Methods: Randomised controlled trial. Adults with type 2 diabetes (n = 120), with HbA1c greater than or equal to 7.5 %, were randomly allocated (4 × 4 block randomised block design) to receive an automated, interactive telephone-delivered management intervention or usual routine care. Baseline sociodemographic, behavioural and medical history data were collected by self-administered questionnaires and biological data were obtained during hospital appointments. Health-related quality of life (HRQL) was measured using the SF-36. Results: The mean age of participants was 57.4 (SD 8.3), 63 % of whom were male. There were no differences in demographic, socioeconomic and behavioural variables between the study arms at baseline. Over the six-month period from baseline, participants receiving the Australian TLC (Telephone-Linked Care) Diabetes program showed a 0.8 % decrease in geometric mean HbA1c from 8.7 % to 7.9 %, compared with a 0.2 % HbA1c reduction (8.9 % to 8.7 %) in the usual care arm (p = 0.002). There was also a significant improvement in mental HRQL, with a mean increase of 1.9 in the intervention arm, while the usual care arm decreased by 0.8 (p = 0.007). No significant improvements in physical HRQL were observed. Conclusions: These analyses indicate the efficacy of the Australian TLC Diabetes program with clinically significant post-intervention improvements in both glycaemic control and mental HRQL. These observed improvements, if supported and maintained by an ongoing program such as this, could significantly reduce diabetes-related complications in the longer term. Given the accessibility and feasibility of this kind of program, it has strong potential for providing effective, ongoing support to many individuals with diabetes in the future

Obstructive sleep apnea, metabolic syndrome, and age: will geriatricians be caught asleep on the job?

Obstructive sleep apnea (OSA) is increasingly recognized in older persons as an important cause of morbidity and mortality, resulting in cardiovascular disease, cognitive dysfunction, and disturbed sleep. It has been cited as an independent risk factor for the metabolic syndrome (MS). The elevated levels of cytokines, such as interleukin-6 and tumor necrosis factor-a, which also increase with age, are a common feature of both OSA and MS. Intermittent hypoxia caused by the recurring episodes of apnea and near-apnea in OSA is a major cause of its systemic effects. Mathematical models of OSA show how obesity and anatomic changes in the upper airways, which may be age-related, interact with the networks responsible for the chemical and neural control of breathing to cause the recurrent intermittent hypoxia of sleep apnea. Treatment of OSA with continuous positive airway pressure improves some aspects of the metabolic syndrome, reduces cardiovascular morbidity, and improves domains of cognitive function. OSA is more difficult to identify in the elderly because many of its symptoms can be caused by other disorders which are common in the elderly. Clinicians who encounter OSA may be advised to search for the presence of MS, and vice versa