M. Halle

Pedometer accuracy in patients with chronic heart failure.

This study assesses the accuracy of the Omron HJ-720ITC pedometer at low walking intensities in patients with chronic heart failure. Step accuracy was assessed by visual observation on the treadmill and during free walking at 40, 50, 60, 70, 80 m/min, as well as during self paced walking using the 6 min walk test. A total of ninety-seven patients with heart failure (mean age: 61+/-13, NYHA I, N=30; NYHA II, N=32; NYHA III, N=35) participated in the study. At predefined walking speeds, a statistically significant % error in pedometer accuracy was evident at 60 m/min (p=0.039), and% error increased markedly below this threshold. Highest% error in pedometer accuracy was seen at 40 m/min (mean bias (% error): 28.3+/-9.0%; 95% CI: 21.8-34.7; p<0.001). During self paced walking (6MWT) the absolute% error in pedometer readings was largest in patients with strongest functional limitations and 6 MWT distances <400 m (mean bias (% error): 10.7+/-13.6%; CI 5.6-15.4, p<0.001). The Omron HJ-720ITC pedometer is accurate for monitoring activity in individuals with normal walking behaviour, but seems unsuitable for chronically ill patients characterised by slow walking gaits.

Clinical and therapeutic use of probucol

SummaryPrevious studies showed that probucol significantly lowered both LDL cholesterol and HDL cholesterol. In addition, there is evidence that as an essential antioxidant probucol causes variations in cellular interactions and cardiovascular functions in patients. Therefore, 14 hypercholesterolemic men were investigated before and during probucol treatment in order to document both serological and cardiovascular changes with special regard to (1) serum apolipoproteins (A-I, A-II, B, C-II, C-III, E) (2) composition and distribution of HDL and LDL subfractions, (3) cardiovascular performance using a maximum exercise stress test, and (4) induced platelet aggregation. In contrast to reduced total, LDL-, and HDL-cholesterol values, highly significant changes in serum apolipoproteins were found in apoA-I only; apoA-II was unchanged both in serum and in HDL subfractions. Despite unchanged serum apoB levels, the results showed that probucol has a significant influence on the composition (TG/FC ratio) of LDL particles of d < 1.019 g/ml. In addition to lipoprotein-related changes, significant decreases in heart rate data and cardiac work and in lactic acid accumulation during exercise were induced by probucol administration; furthermore, adrenaline-induced platelet aggregation was also decreased. The results found significantly demonstrate that probucol acts by way of more mechanisms than cholesterol lowering alone. This aspect may be of special interest in the clinical use of probucol, because a coronary-risk-reducing therapy should not affect the lipoprotein profile only.

Physical exercise in dyslipoproteinemias: An update

Epidemiological as well as interventional studies have proven a significant link between the lipoprotein profile and cardiovascular morbidity and mortality. As physical activity is accepted as an important factor in improving physical fitness and lipoprotein metabolism, there is evidence that physically active men have a lower cardiovascular risk as a benefit of their higher metabolic fitness. Physical activity and physical fitness are generally linked to higher physical fitness and lower LDL cholesterol as well as lower triglycerides accompanied by a favorable body composition. Both in healthy men as well as in patients, the impact of fitness and training is often more impressive when lipoprotein subclasses, particularly HDL 2 and LDL6 cholesterol levels, are taken into account. These observations indicate that the preventive and therapeutic use of physical activity is of particular significance in populations with dyslipoproteinemia and reduced daily activities. Furthermore, to optimize the therapeutic benefit of physical activity and lifestyle programs, increased attention should be paid to characterizing and motivating subgroups that will particularly profit by exercise intervention and lifestyle changes.

Temporal oscillations of retinal vessel diameter in healthy volunteers of different age

PURPOSE We investigated whether temporal oscillations of the retinal vessel diameter, as measured with the dynamic vessel analyzer (DVA), undergo age-related changes. METHODS Vessel diameters of retinal arterial and venous segments were examined with the DVA in 28 medically healthy volunteers divided into two age groups of 14 persons each: young subjects (21-32 years) and seniors (52-70 years). Continuous temporal records of vessel diameter were mathematically evaluated and divided into high-frequency (period <1.5 s) and low-frequency (period > or =1.5 s) oscillations. RESULTS The phase difference between temporal arterial and venous vessel diameter records was higher in the young group [0.6 (0.1, 3.3)] s [median (1st quartile, 3rd quartile)] compared with the seniors [0.1 (-0.4, 0.3) s]. There was a difference in the periodicity in veins between the groups and, in seniors, between the arteries and the veins. CONCLUSIONS High-frequency oscillations of vessel diameter correspond to the heartbeat. These were expressed more in seniors. Low-frequency oscillations were well expressed in young subjects. Our results show significant age-related alterations in retinal vessel regulation.

Stellenwert von körperlicher Mehraktivität in der ambulanten kardiovaskulären Prävention

Die aktuellen Tendenzen im Gesundheitswesen liefern gewichtige Gründe, in der Primärprävention der Arteriosklerose einen körperlich aktiven Lebensstil stärker zu propagieren und in der Sekundärprävention von kardiovaskulären Erkrankungen, insbesondere der koronaren Herzkrankheit, eine ambulante Bewegungstherapie zukünftig vermehrt zu verordnen. Regelmäßige körperliche Mehraktivität eröffnet eine therapeutische Möglichkeit, die atherogenen Risikofaktoren (Übergewicht, Hypertonie, Dyslipoproteinämie, Insulinresistenz, Thrombogenese) günstig zu beeinflussen. Körperliche Mehraktivität ist mit einer Modifizierung der Körperkomposition zugunsten des Muskelanteils verbunden und führt zu Veränderungen des Ernährungsverhaltens und der allgemeinen Lebensweise. Der Verzehr von fettärmeren, stärker vegetarisch ausgerichteten Nahrungsmitteln unterstützt die Regulierung des Körpergewichtes und der übrigen metabolischen Risikofaktoren. Alle genannten Veränderungen sind dem arteriosklerotischen Gefäßprozeß entgegengerichtet und vermindern das Risiko eines akuten thromboembolischen arteriellen Gefäßverschlusses. Für eine eigeninitiativ praktizierte körperliche Mehraktivität zur Primärprävention bzw. eine ärztlich überwachte Bewegungstherapie in Herzgruppen zur Sekundärprävention der Arteriosklerose eignet sich vorzugsweise ein niedrig intensives, aerobes Ausdauertraining. Die Intensitäten der absolvierten Belastungen können mittels Laktatbestimmungen im Kapillarblut objektiviert und reguliert werden. Der durch die körperliche Mehraktivität induzierte wöchentliche Energiemehrumsatz sollte mindestens 1000 bis maximal 3500 kcal betragen. Er kann durch einen erhöhten kalorischen Basisverbrauch im Alltag (z.B. Treppensteigen, Spazierengehen, Gartenarbeit) und/oder durch eine regelmäßige körperliche Aktivität in der Freizeit realisiert werden und sollte mindestens 300 kcal/Einheit (z.B. Ergometertraining mit 100 W über 40 min) beinhalten. Langzeitstudien über den Nutzen einer primären und sekundären kardiovaskulären Prävention zeigen eine Absenkung der kardiovaskulären Mortalität um 20–30%. Current trends in public health provided potential arguments to, first, intensify the recommendations of a physically active lifestyle in the primary prevention of atherosclerosis and, second, to prescribe a supervised outpatient exercise training program for secondary prevention of cardiovascular diseases. Regular physical exercise may positively influence cardiovascular risk factors (overweight, hypertension, hyperlipoproteinaemia, insulin resistance, hemostatic markers). Physical conditioning modifies the body composition in favor of an increased skeletal muscle mass, changes the eating habits, and other life style characteristics. The dietary modifications characterized by a low-fat, more vegetarian food supports the weight control and the adjustment of the other metabolic risk factors. All these changes are suitable to reduce the manifestation of atherosclerosis and to minimize the risk of an acute thromboembolic arterial occlusion. Physical conditioning on ones own initiative in primary prevention or an exercise training program supervised by health professionals in secondary prevention of atherosclerosis should predominantly include a low intensive aerobic endurance exercise training. Lactate concentration in capillary blood can be measured to objectify and regulate exercise intensity. The additional energy turnover should amount to a minimum of 1,000 kcal and a maximum of 3,500 kcal weekly. This energy expenditure could be realized either with an increased physical activity level in daily routine (e.g., stair climbing, go for a walk, gardening) or by a regular leisure-time physical exercise. A turnover of 300 kcal per session should be prescribed. In long-term clinical trials investigating the benefit of primary and secondary cardiovascular prevention a reduction of the cardiovascular mortality of about 20–30% has been demonstrated.

LDL-Subfraktionen und koronare Herzerkrankung — Eine Übersicht

Die Klasse der Low-density-Lipoproteine (LDL) ist nicht homogen, sondern setzt sich aus einem heterogenen Partikelspektrum mit unterschiedlichen physiko-chemischen Eigenschaften zusammen. Hinsichtlich Partikelgröße und -dichte kann die LDL-Fraktion in Unterfraktionen aufgetrennt werden. Zwei LDL-Subfraktionsprofile werden unterschieden: ein “LDL-Phänotyp A” mit erhöhter Konzentration großer, weniger dichter LDL-Partikel und ein “LDL-Phänotyp B” mit erhöhter Konzentration kleiner, dichter LDL-Partikel. Letzteres Profil ist besonders bei erhöhter Insulinresistenz ausgeprägt und gleichzeitig mit erhöhten Serumtriglyzeriden und erniedrigten Konzentrationen von HDL- und insbesondere HDL2-Cholesterin assoziiert. In klinischen Studien hat sich eine erhöhte Konzentration kleiner LDL-Partikel als Prädiktor einer erhöhten Inzidenz kardiovaskulärer Erkrankungen gezeigt. Erklärt wird dies mit einer erhöhten Oxidierbarkeit und vermehrten subendothelialen Ablagerung kleiner LDL- im Vergleich zu großen LDL-Partikeln. Das LDL-Profil ist zu ungefährt 30% genetisch determiniert, kann aber sowohl durch nichtpharmakologische (körperliche Aktivität und Diät) wie auch pharmakologische (Lipidsenker) Intervention im Sinne einer Senkung kleiner LDL-Partikel günstig beeinflußt werden. Obwohl auch prospektive Studien die Bedeutung kleiner LDL-Partikel für die Atherosklerose bestätigen konnten, ist trotzdem noch nicht eindeutig bewiesen, inwieweit das LDL-Profil einen unabhängigen und eigenständigen Lipidrisikofaktor neben HDL2-Cholesterin und Triglyzeriden darstellt. Das LDL-Subfraktionsprofil ist aber ein wichtiger metabolischer Indikator einer multifaktoriellen kardiovaskulären Risikokonstellation. Low density lipoproteins are heterogeneous in particle size, density, and physical as well as chemical properties. Regarding size and density, LDL can be divided into two main profiles, LDL pattern A with elevated concentration of large, buoyant LDL particles and LDL pattern B with increased concentration of small, dense LDL particles. The latter is particularly expressed in insulin resistance and is associated with elevated serum triglycerides and reduced concentrations of HDL and particularly HDL2 cholesterol. The LDL profile of increased concentration of small, dense LDL particles has shown to be associated with an increased risk of cardiovascular events. The LDL profile is partly genetically determined, but can be improved by non-pharmacological (exercise, diet) and pharmacological intervention. It remains to be confirmed whether the LDL subfraction profile is an independent lipid risk factor besides HDL2 cholesterol and triglycerides, but it is certainly a valuable indicator assessing metabolic cardiovascular risk.

Zeitliche Schwingungen retinaler Gefäßdurchmesser bei Gesunden unterschiedlichen Alters@@@Temporal oscillations of retinal vessel diameter in healthy volunteers of different age: Kreuz- und Autokorrelation für dynamische Gefäßanalyse

PURPOSE We investigated whether temporal oscillations of the retinal vessel diameter, as measured with the dynamic vessel analyzer (DVA), undergo age-related changes. METHODS Vessel diameters of retinal arterial and venous segments were examined with the DVA in 28 medically healthy volunteers divided into two age groups of 14 persons each: young subjects (21-32 years) and seniors (52-70 years). Continuous temporal records of vessel diameter were mathematically evaluated and divided into high-frequency (period <1.5 s) and low-frequency (period > or =1.5 s) oscillations. RESULTS The phase difference between temporal arterial and venous vessel diameter records was higher in the young group [0.6 (0.1, 3.3)] s [median (1st quartile, 3rd quartile)] compared with the seniors [0.1 (-0.4, 0.3) s]. There was a difference in the periodicity in veins between the groups and, in seniors, between the arteries and the veins. CONCLUSIONS High-frequency oscillations of vessel diameter correspond to the heartbeat. These were expressed more in seniors. Low-frequency oscillations were well expressed in young subjects. Our results show significant age-related alterations in retinal vessel regulation.

Mehrfach ungesättigte Fettsäuren, koronare Herzerkrankung und Diabetes mellitus Typ II – Hinweise für den Stellenwert von Gamma-Linolensäure

Sowohl bei kardiovaskulAren Erkrankungen als auch bei Diabetes mellitus Typ II nehmen mehrfach ungesAttigte FettsAuren in hohem Masse Einfluss auf die Regulation physiologischer und pat