Association between VO2 peak estimated by a 1-km treadmill walk and mortality. A 10-year follow-up study in patients with cardiovascular disease

Purpose

The aim of this study is to assess the association between peak oxygen uptake (VO₂ peak), determined using a perceptually regulated 1-km walking test (1 k-TWT), and all-cause mortality in cardiac patients.

Methods

1255 male patients, aged 25–85 years, completed a moderate 1 k-TWT to estimate VO₂ peak. Subjects were followed for all-cause mortality for up to 10 years. Cox proportional hazard models were employed to determine variables associated with mortality. Based on the estimated VO₂ peak, the sample was subdivided into quartiles and mortality risks were calculated. To assess the discriminatory accuracy of the estimated VO₂ peak for estimating survival, receiver-operating-characteristics curves were constructed.

Results

During a median 8.2 year follow-up, a total of 141 deaths from any cause occurred, yielding an average annual mortality of 1.4%. The strongest predictor of all-cause mortality was the estimated VO₂ peak (c-statistic 0.71, 95% confidence intervals: 0.69–0.74, P < 0.0001). Survival decreased in a graded fashion from the highest estimated VO₂ peak quartile to the lowest quartile. Compared to the lowest quartile, the hazard ratios (95% confidence intervals) for the second, third, and fourth quartiles were 0.77 (0.35–1.33), 0.43 (0.20–0.91), and 0.16 (0.05–0.54) respectively (P for trend < 0.0001). An 89% reduction in mortality risk was observed among a subset of subjects in the fittest quartile who improved their estimated VO₂ peak over the follow-up period relative to subjects in the least fit quartile who did not improve.

Conclusion

VO₂ peak estimated by a novel 1 k-TWT predicts survival in subjects with stable cardiovascular disease.     

Myasthenia gravis: a changing pattern of incidence

The annual incidence of myasthenia gravis (MG) ranges from 3 to 30 per 1,000,000 people. Since the mid-1980s, an increasing incidence has been reported, mainly due to late-onset MG. Whether the increase was due to population aging, improved diagnosis and case collection, or a true excess of incidence cases is still under debate. We used a complete enumeration approach by reviewing all possible sources of case collection in the province of Ferrara, Italy, to estimate the MG incidence and its temporal trend over the study period (1985–2007). The mean annual age-adjusted incidence of MG was 18 per 1,000,000, without any significant temporal trend. The incidence rates in the period 1985–1990 were 14 both for early and late-onset MG. Thereafter, a significant increase in incidence of late-onset MG (p < 0.05), and a decrease in early onset MG were detected (p < 0.01). These findings were related to nonthymoma MG. The median age at onset of the disease steadily increased over time. A changing pattern of MG incidence with an increase in frequency of late-onset and a decrease of early onset MG was found in the last years, giving a significant shift to older age at onset of the disease. Unknown environmental factors may have driven this change in MG epidemiology.     

Treatment with angiotensin-converting enzyme inhibitors is associated with a reduction in short-term mortality in older patients with acute ischemic stroke

BACKGROUND: Stroke is the third cause of death in older people living in Western countries. We tested the hypothesis that angiotensin-converting enzyme inhibitors (A-I) might affect short-term (30 day) mortality in older persons with severe acute ischemic stroke. METHODS: We analyzed data from a retrospective study including 475 consecutive older patients hospitalized for acute ischemic stroke. Mean age was 78.4 +/- 9.2 years; 58.2% were female. Stroke type was classified according to the Oxford Community Stroke Project (OCSP). RESULTS: Mortality rate was 28%. Thirty-two percent of patients were treated with A-I; mortality was 16.5% in patients treated compared with 33.3% in those not treated (chi(2) p =.001). The odds ratio for mortality in treated patients was: 0.47 (0.25-0.89) after full adjustment (age, sex, mean diastolic and systolic blood pressure, previous stroke and/or transient ischemic attack, congestive heart failure, atrial fibrillation, diabetes, hypertension, coronary heart disease, and previous treatment with A-I); 0.29 (0.09-0.89) in patients with altered level of consciousness after full adjustment; 0.60 (0.33-1.12) after adjustment for OCSP classification, age, and sex; and 0.30 (0.08-0.97) in total anterior circulation infarction stroke type after full adjustment. CONCLUSIONS: Our data suggest that treatment with A-I might reduce short-term mortality in older patients with acute ischemic stroke. Randomized clinical trials should confirm this possible specific effect of A-I.     

Herbal mixtures in the traditional medicine of eastern Cuba

Herbal mixtures in the traditional medicine of Eastern Cuba. Traditional herbal mixtures in Eastern Cuba are investigated through interviews with 130 knowledgeable people and traditional healers of the provinces of Santiago de Cuba and Guantánamo. One hundred seventy plant species and other products are used in 199 formulas, galones being the more complex. Cocos nucifera L. (Arecaceae), Bidens pilosa L. (Asteraceae), Cissus sicyoides L. (Vitaceae), Erythroxylum havanense Jacq. (Erythroxylaceae) and Stachytarpheta jamaicensis (L.) Vahl. (Verbenaceae) are the species most frequently cited. The ecological distribution of the taxa and cultural and anthropological aspects of mixtures are highlighted; particularly American and African influences that have shaped local knowledge about plant combinations are discussed.     

Body composition in underweight elderly subjects: reliability of bioelectrical impedance analysis

BACKGROUND AND AIMS: In underweight elderly subjects it is important to estimate body composition and particularly fat-free mass (FFM). Bioelectrical impedance analysis (BIA) is a non-invasive method in determining FFM, but its usefulness in these frail subjects should be verified. The aim of this study is to verify in underweight elderly people the reliability of previously published BIA formulas in detecting FFM. METHODS: Fifty-seven hospitalized elderly subjects (27 males and 30 females) with body mass index <20 kg/m(2) were selected. In all subjects, FFM was detected by dual energy X-ray absorptiometry. Moreover, BIA measurements were performed at standard frequency (50 kHz and 800 microA) and FFM was derived using the main previous published BIA equations. Results: In men, Kyle and Rising equations gave acceptable estimates of FFM with a mean error, respectively, of 1+/-1.9 and 1.4+/-1.7 kg. Also RJL formula could be used after adjusting for a correction factor. In women, no equation seemed sufficiently reliable to estimate FFM. CONCLUSIONS: BIA method seems useful to evaluate body composition in underweight elderly men but it seems to have intrinsic limits in women. Nevertheless, the variability in behavior of the different equations suggests to be careful in adopting BIA equations.     

The value of serum albumin and high-density lipoprotein cholesterol in defining mortality risk in older persons with low serum cholesterol

OBJECTIVES: To investigate the relationship between low cholesterol and mortality in older persons to identify, using information collected at a single point in time, subgroups of persons with low and high mortality risk. DESIGN: Prospective cohort study with a median follow-up period of 4.9 years. SETTINGS: East Boston, Massachusetts; New Haven, Connecticut; and Iowa and Washington counties, Iowa. PARTICIPANTS: Four thousand one hundred twenty-eight participants (64% women) age 70 and older at baseline (mean 78.7 years, range 70-103); 393 (9.5%) had low cholesterol, defined as < or =160 mg/dl. MEASUREMENTS: All-cause mortality and mortality not related to coronary heart disease and ischemic stroke. RESULTS: During the follow-up period there were 1,117 deaths. After adjustment for age and gender, persons with low cholesterol had significantly higher mortality than those with normal and high cholesterol. Among subjects with low cholesterol, those with albumin> 38 g/L had a significant risk reduction compared with those with albumin < or =38 g/L (relative risk (RR) = 0.57; 95% confidence interval (CI) = 0.41-0.79). Within the higher albumin group, high-density lipoprotein cholesterol (HDL-C) level further identified two subgroups of subjects with different risks; participants with HDL-C <47 mg/dl had a 32% risk reduction (RR = 0.68; 95% CI = 0.47-0.99) and those with HDL-C > or =47 mg/dl had a 62% risk reduction (RR = 0.38; 95% CI = 0.20-0.68), compared with the reference category; those with albumin < or =38 g/L and HDL-C <47 mg/dl. CONCLUSIONS: Older persons with low cholesterol constitute a heterogeneous group with regard to health characteristics and mortality risk. Serum albumin and HDL-C can be routinely used in older patients with low cholesterol to distinguish three subgroups with different prognoses: (1) high risk (low albumin), (2) intermediate risk (high albumin and low HDL-C), and (3) low risk (high albumin and high HDL-C).