Jochen Klenk

Obesity and incidence of cancer : a large cohort study of over 145,000 adults in Austria

We investigated the relation of overweight and obesity with cancer in a population-based cohort of more than 145 000 Austrian adults over an average of 9.9 years. Incident cancers (n=6241) were identified through the state cancer registry. Using Cox proportional-hazards models adjusted for smoking and occupation, increases in relative body weight in men were associated with colon cancer (hazard rate (HR) ratio 2.48; 95% confidence interval (CI): 1.15, 5.39 for body mass index (BMI) ⩾35 kg m−2) and pancreatic cancer (HR 2.34, 95% CI: 1.17, 4.66 for BMI>30 kg m−2) compared to participants with normal weight (BMI 18.5–24.9 kg m−2). In women, there was a weak positive association between increasing BMI and all cancers combined, and strong associations with non-Hodgkins lymphomas (HR 2.86, 95% CI: 1.49, 5.49 for BMI⩾30 kg m−2) and cancers of the uterine corpus (HR 3.93, 95% CI: 2.35, 6.56 for BMI⩾35 kg m−2). Incidence of breast cancer was positively associated with high BMI only after age 65 years. These findings provide further evidence that overweight is associated with the incidence of several types of cancer.

Evaluation of Accelerometer-Based Fall Detection Algorithms on Real-World Falls

Despite extensive preventive efforts, falls continue to be a major source of morbidity and mortality among elderly. Real-time detection of falls and their urgent communication to a telecare center may enable rapid medical assistance, thus increasing the sense of security of the elderly and reducing some of the negative consequences of falls. Many different approaches have been explored to automatically detect a fall using inertial sensors. Although previously published algorithms report high sensitivity (SE) and high specificity (SP), they have usually been tested on simulated falls performed by healthy volunteers. We recently collected acceleration data during a number of real-world falls among a patient population with a high-fall-risk as part of the SensAction-AAL European project. The aim of the present study is to benchmark the performance of thirteen published fall-detection algorithms when they are applied to the database of 29 real-world falls. To the best of our knowledge, this is the first systematic comparison of fall detection algorithms tested on real-world falls. We found that the SP average of the thirteen algorithms, was (mean±std) 83.0%±30.3% (maximum value = 98%). The SE was considerably lower (SE = 57.0%±27.3%, maximum value = 82.8%), much lower than the values obtained on simulated falls. The number of false alarms generated by the algorithms during 1-day monitoring of three representative fallers ranged from 3 to 85. The factors that affect the performance of the published algorithms, when they are applied to the real-world falls, are also discussed. These findings indicate the importance of testing fall-detection algorithms in real-life conditions in order to produce more effective automated alarm systems with higher acceptance. Further, the present results support the idea that a large, shared real-world fall database could, potentially, provide an enhanced understanding of the fall process and the information needed to design and evaluate a high-performance fall detector.

Enlarged Substantia Nigra Hyperechogenicity and Risk for Parkinson Disease: A 37-Month 3-Center Study of 1847 Older Persons

OBJECTIVE To evaluate whether enlarged substantia nigra hyperechogenicity (SN+) is associated with an increased risk for Parkinson disease (PD) in a healthy elderly population. DESIGN Longitudinal 3-center observational study with 37 months of prospective follow-up. SETTING Individuals 50 years or older without evidence of PD or any other neurodegenerative disease. PARTICIPANTS Of 1847 participants who underwent a full medical history, neurological assessment, and transcranial sonography at baseline, 1535 could undergo reassessment. MAIN OUTCOME MEASURE Incidence of new-onset PD in relation to baseline transcranial sonography status. RESULTS There were 11 cases of incident PD during the follow-up period. In participants with SN+ at baseline, the relative risk for incident PD was 17.37 (95% confidence interval, 3.71-81.34) times higher compared with normoechogenic participants. CONCLUSIONS In this prospective study, we demonstrate for the first time a highly increased risk for PD in elderly individuals with SN+. Transcranial sonography of the midbrain may therefore be a promising primary screening procedure to define a risk population for imminent PD.

Hip fractures in institutionalized elderly people: incidence rates and excess mortality.

It is assumed that nursing homes are the setting with the highest incidence of hip fractures. This observation is, however, based on very little data. The aim of this study was to analyze hip fracture rates and the associated excess mortality in a large nursing home population. A cohort of >69,000 women and men newly admitted to German nursing homes were used to calculate sex‐ and age‐specific incidence rates of hip fractures. To calculate excess mortality, a retrospective cohort study was conducted. To each patient with a hip fracture (n = 4342), four residents without hip fracture (n = 17,368) were matched by sex, age, and level of care (measure for the need of care). Hazard regression models were applied. During 91,850 person‐years, 4342 hip fractures were observed. The crude incidence rates for hip fractures were 50.8/1000 person‐years in women and 32.7/1000 person‐years in men. The incidence rates increased with increasing age categories and were highest in the first months after admission to the nursing home. Increasing care need reduced the risk of hip fracture. Mortality in patients with a hip fracture was increased (women: hazard rate ratio for the first 3 mo after fracture, 1.72; 95% CI, 1.59–1.86; men: hazard ratio, 2.14; 95% CI, 1.80–2.53), but excess mortality was limited to the first months after injury. Data are presented for hip fracture rates and excess mortality after a hip fracture. Our results have implications on the timing and the allocation of specific measures for hip fracture prevention.

Influence of Having Breakfast on Cognitive Performance and Mood in 13- to 20-Year-Old High School Students: Results of a Crossover Trial

OBJECTIVE. The goal was to determine whether breakfast had effects on the cognitive performance and mood of high school students. METHODS. A crossover trial was performed in boarding schools, involving 104 students between 13 and 20 years of age. The participants were randomly assigned to 2 equal-size groups on the morning of the first testing day. One half of the total sample received a standardized breakfast, whereas the other half received no breakfast. Seven days later, the treatment order was reversed. Measurements of cognitive function included standardized tests of attention and concentration, as well as tests of verbal and spatial memory. In addition, mood was rated with a self-administered questionnaire covering the dimensions of positive and negative affect, information uptake, arousal, and alertness. Statistical analysis consisted of repeated-measures analysis of variance. RESULTS. Breakfast had no effect on sustained attention among high school students. Visuospatial memory was improved in male students. Self-reported alertness improved significantly in the entire study population. Male students reported feeling more positive after consuming breakfast, compared with the fasting condition. CONCLUSIONS. This crossover trial demonstrated positive short-term effects of breakfast on cognitive functioning and self-reported alertness in high school students.

Longitudinal change in serum gamma-glutamyltransferase and cardiovascular disease mortality: a prospective population-based study in 76,113 Austrian adults.

Objective—The purpose of this study was to investigate the association of longitudinal change in serum γ-glutamyltransferase (GGT) with mortality from cardiovascular disease (CVD). Methods and Results—A population-based cohort of 76 113 Austrian men and women with 455 331 serial GGT measurements was prospectively followed-up for a median of 10.2 years after assessment of longitudinal GGT change during an average period of 6.9 years. Cox proportional hazards regression with time-varying covariates was used to evaluate GGT change as an independent predictor for CVD death. Independently of baseline GGT and other classical CVD risk factors, a pronounced increase in GGT (7-year change >9.2 U/L) was significantly associated with increased total CVD mortality in men (P=0.005); the adjusted hazard ratio (95% confidence interval) in comparison to stable GGT (7-year change −0.7 to 1.3 U/L) was 1.40 (1.09 to 1.81). Similarly, total CVD risk was elevated for increasing GGT in women, although effects were less pronounced and statistically significant only in subanalyses regarding coronary heart disease. Age of participants significantly modified the relation between GGT change and CVD mortality, with markedly stronger associations to be observable for younger individuals. Conclusion—Our study is the first to demonstrate that a longitudinal increase in GGT, independently of baseline GGT and even within its normal range, significantly increases risk of fatal CVD.

Analyses of case-control data for additional outcomes

Consider a case–control study in which prevalent cases of a given disease define the index series and members of the base population without the disease are sampled to provide the referent series. Information on a set of explanatory variables (eg, genotypes) is collected at great cost for cases and controls. The objective of the study is to evaluate the relationship between case status and the explanatory variables. Subsequently, an investigator notes that the prevalence of a second disease was measured for the members of the index and referent series. The investigator wishes to make efficient use of the available data by assessing the relationship between this second disease and the set of explanatory variables. In this paper, we discuss 2 analytic approaches that might be used to assess associations between the explanatory variables and an outcome other than the original disease. One is through the inclusion of a design variable for original disease status as a covariate; and, the second is through weighted logistic regression using the inverse of the sampling fractions as the weights. The latter approach allows the investigator to derive an estimate of association between the explanatory variables and the second disease without adjustment for the first disease. Weighted logistic regression methods are readily implemented using available statistical packages.

Smartphone-based solutions for fall detection and prevention: the FARSEEING approach.

Falls are not an inevitable consequence of aging. The risk and rate of falls can be reduced. Recent improvements in smartphone technology enable implementation of a wide variety of services and applications, thus making the smartphone more of a digital companion than simply a communication tool. This paper presents the results obtained by the FARSEEING project where smartphones are one example of intervention in a population-based scenario. The applications developed take advantage of the smartphone-embedded inertial sensors and require that subjects wear the smartphone by means of a waist belt. The uFall Android application has been developed for monitoring the user’s motor activities at home. The application does not require any direct interaction with the user and it is also capable of running a real-time fall-detection algorithm. uTUG is a stand-alone application for instrumenting the Timed Up and Go test, which is a test often included in fall risk assessment protocols. The application acts like a pocket-sized motion laboratory, since it is capable not only of recording the trial but also of processing the data and immediately displaying the results. uTUG is designed to be self-administrable at home.ZusammenfassungStürze sind keine notwendige Folge des Alterns, sie können verhindert werden. Die jüngsten Entwicklungen der Smartphonetechnologie ermöglichen eine Vielzahl von Anwendungen und Applikationen, wodurch das Gerät nicht nur als Kommunikationswerkzeug, sondern zunehmend als digitaler Alltagsbegleiter dient. In diesem Artikel werden Ergebnisse des FARSEEING-Projekts präsentiert, bei dem Smartphones ein Interventionsbeispiel in einem populationsbezogenen Szenario sind. Die hier vorgestellten Applikationen nutzen die im Gerät integrierten Inertialsensoren. Das Smartphone wird dabei mit einem Hüftgurt getragen. Die uFall-Applikation dient zur innerhäuslichen Beobachtung der körperlichen Aktivität des Nutzers und ermöglicht eine algorithmusbasierte Echtzeitsturzerkennung. Die uTUG-Applikation instrumentalisiert den Timed-up-and-go(TUG)-Test (Zeit bis zum Aufstehen und Gehen), welcher häufig zur Messung des Sturzrisikos verwendet wird. Dieses „miniaturisierte Bewegungslabor“ erlaubt nicht nur die Durchführung einzelner Messungen, sondern stellt auch prozessierte Daten zur direkten Auswertung bereit. Die Applikationen ermöglichen die Eigenanwendung und erfordern keine direkte Interaktion des Nutzers mit dem Gerät.

Prospective study of the association of gamma-glutamyltransferase with cancer incidence in women†

Although several epidemiologic studies have shown that gamma‐glutamyltransferase (GGT) is associated with cardiovascular disease and all‐cause mortality, its relationship with cancer incidence remains widely unexplored. In experimental models the ability of cellular GGT to modulate crucial redox‐sensitive functions has been established, and it may thus play a role in tumor progression. In the present study, we investigated the association of GGT with overall and site‐specific cancer incidence in a population‐based cohort of 92,843 Austrian women with 349,674 serial GGT measurements, prospectively followed‐up for a median of 13.5 years. The relationship between GGT and cancer incidence was analyzed using adjusted Cox regression models with age as underlying time metric with age as underlying time metric including GGT concentrations at baseline and incorporating repeated GGT measurements as a time‐dependent variable. During follow‐up, 4,884 incidence cancers were observed. Compared to normal low GGT (<17.99 U/L), cancer risk was elevated for all other GGT categories (p for trend < 0.0001), with adjusted hazard ratios (95% confidence intervals) of 1.06 (0.99–1.13) for GGT levels between 18.00 and 35.99 U/L (normal high), 1.12 (1.02–1.22) for GGT levels between 36.00 and 71.99 U/L (elevated) and 1.43 (1.28–1.61) for highly elevated GGT (>72.00 U/L). Very similar results were seen when GGT was analyzed as a time‐dependent variable. In cancer‐site specific models, elevated GGT statistically significantly increased the risk for malignant neoplasms of digestive organs, the respiratory system/intrathoracic organs, breast and female genital organs and lymphoid and haematopoietic cancers (all, p < 0.006). Our study is the first to demonstrate in a large population‐based cohort that high GGT levels significantly increased cancer risk in women. Published 2008 Wiley‐Liss, Inc.

Serum triglyceride concentrations and cancer risk in a large cohort study in Austria.

Background:Blood lipid levels as part of the metabolic syndrome are thought to be linked to cancer risk. Few epidemiological studies have addressed the association between serum triglyceride (STG) concentrations and cancer risk.Methods:Serum triglyceride concentrations were collected in a health investigation (1988–2003). The analyses included 156 153 subjects (71 693 men and 84 460 women), with 5079 incident cancers in men and 4738 cancers in women, and an average of 10.6 years of follow-up. All malignancies were ascertained from the population cancer registry. Multivariate Cox proportional hazard models stratified by age and sex were used to determine adjusted cancer risk estimates and 95% confidence interval (95% CI).Results:In men and women combined, higher STG concentrations were associated with increased risk of lung (4th vs 1st quartile: HR, 1.94; 95% CI, 1.47–2.54), rectal (HR, 1.56; 95% CI, 1.00–2.44), and thyroid cancer (HR, 1.96; 95% CI, 1.00–3.84). Serum triglyceride concentrations were inversely associated with non-Hodgkins lymphoma. In men, STG concentrations were inversely associated with prostate cancer and positively with renal cancer. In women, STG concentrations were positively associated with gynaecological cancers. Stratification by BMI revealed a higher risk of gynaecological cancers in overweight than in normal weight women. No other associations were found.Conclusions:Our findings support the hypothesis that STG concentrations are involved in the pathogenesis of lung, rectal, thyroid, prostate, and gynaecological cancers.