Arja Nenonen

Effect of 8‐Month Vertical Whole Body Vibration on Bone, Muscle Performance, and Body Balance: A Randomized Controlled Study

Recent animal studies have given evidence that vibration loading may be an efficient and safe way to improve mass and mechanical competence of bone, thus providing great potential for preventing and treating osteoporosis. Randomized controlled trials on the safety and efficacy of the vibration on human skeleton are, however, lacking. This randomized controlled intervention trial was designed to assess the effects of an 8‐month whole body vibration intervention on bone, muscular performance, and body balance in young and healthy adults. Fifty‐six volunteers (21 men and 35 women; age, 19‐38 years) were randomly assigned to the vibration group or control group. The vibration intervention consisted of an 8‐month whole body vibration (4 min/day, 3‐5 times per week). During the 4‐minute vibration program, the platform oscillated in an ascending order from 25 to 45 Hz, corresponding to estimated maximum vertical accelerations from 2g to 8g. Mass, structure, and estimated strength of bone at the distal tibia and tibial shaft were assessed by peripheral quantitative computed tomography (pQCT) at baseline and at 8 months. Bone mineral content was measured at the lumbar spine, femoral neck, trochanter, calcaneus, and distal radius using DXA at baseline and after the 8‐month intervention. Serum markers of bone turnover were determined at baseline and 3, 6, and 8 months. Five performance tests (vertical jump, isometric extension strength of the lower extremities, grip strength, shuttle run, and postural sway) were performed at baseline and after the 8‐month intervention. The 8‐month vibration intervention succeeded well and was safe to perform but had no effect on mass, structure, or estimated strength of bone at any skeletal site. Serum markers of bone turnover did not change during the vibration intervention. However, at 8 months, a 7.8% net benefit in the vertical jump height was observed in the vibration group (95% CI, 2.8‐13.1%; p = 0.003). On the other performance and balance tests, the vibration intervention had no effect. In conclusion, the studied whole body vibration program had no effect on bones of young, healthy adults, but instead, increased vertical jump height. Future human studies are needed before clinical recommendations for vibration exercise.

Serum TRACP 5b is a useful marker for monitoring alendronate treatment: comparison with other markers of bone turnover

We studied clinical performance of serum TRACP 5b and other bone turnover markers, including S‐CTX, U‐DPD, S‐PINP, S‐BALP, and S‐OC, for monitoring alendronate treatment. TRACP 5b had higher clinical sensitivity, area under the ROC curve, and signal‐to‐noise ratio than the other markers.

A controlled trial of the health benefits of regular walking on a golf course

PURPOSE To study the effects of regular walking during a golf game on various health and fitness indicators in middle-aged men. METHODS Study subjects were 55 healthy male golfers aged 48 to 64 years who had been sedentary during the 7 months before the study, and 55 age-matched, similarly sedentary controls. During the 20-week study, those in the intervention group were encouraged to play golf two to three times a week; the controls were not. Measurements of body composition, cardiorespiratory performance, motor and musculoskeletal fitness, blood pressure, and serum lipid, glucose, and insulin levels were obtained at baseline and after the 20-week study. RESULTS Walking during a golf game was a practical and safe form of physical activity with high adherence. It significantly increased aerobic performance and trunk muscle endurance, with a net difference (pretraining to posttraining change between the golfers and controls) of 36 seconds (95% confidence interval [CI]: 19 to 53 seconds, P < 0.001) for treadmill walking time and 13 seconds (95% CI: 2 to 24 seconds, P = 0.02) for static back extension. In addition, regular walking favorably affected body composition, including reductions in weight of 1.4 kg (95% CI: 0.6 to 2.1 kg, P < 0.001), in waist circumference of 2.2 cm (95% CI: 1.0 to 3.3 cm, P < 0.001), and in abdominal skin fold thickness of 2.2 cm (95% CI: 0.9 to 3.4 cm, P = 0.001). Golfers also had significantly greater increases in serum high-density lipoprotein (HDL) cholesterol levels and in the ratio of HDL cholesterol to total cholesterol. CONCLUSIONS Regular walking had many positive effects on the health and fitness of sedentary middle-aged men. Walking during a golf game is characterized by high adherence and low risk of injury and is therefore a good form of health-enhancing physical activity.

Effect of Long-Term Endurance and Strength Training on Metabolic Control and Arterial Elasticity in Patients With Type 2 Diabetes Mellitus

Poor glucose control increases the risk of vascular complications and cardiovascular mortality in patients with diabetes mellitus (DM). Our aim was to evaluate the efficacy of a long-term exercise training program on metabolic control and arterial stiffness in patients with type 2 DM. Fifty men with DM (age 52.3 +/- 5.6 years) were randomly assigned to the exercise training (E) or standard treatment for DM (control [C]) group for 24 months. Supervised exercise training included both endurance and muscle strength training 4 times/week. All exercise sessions were controlled by heart rate and intensity. Glycated hemoglobin A1c, insulin, leptin, blood lipids, blood pressure, maximal oxygen consumption in spiroergometry, and muscle strength were measured every 6 months. Arterial stiffness was assessed by measuring pulse wave velocity. Maximal oxygen consumption in spiroergometry (E 31.9 to 34.8 vs C 32.6 to 31.8 ml/kg/min; p = 0.003), muscle strength (sit-up test, E 12.7 to 20.8 vs C 14.6 to 13.1 times; p <0.001), hemoglobin A1c (E 8.2% to 7.6% vs C 8.0% to 8.3%; p = 0.006), and leptin (E 7.4 to 6.7 vs C 7.4 to 7.9 microg/L; p = 0.013) improved significantly in the E group, but no change or worsening in these variables occurred in the C group. Body weight was not different between groups at 2 years. However, pulse wave velocity increased in both groups (E +0.600 vs C +1.300 m/s; p = 0.27). In conclusion, long-term endurance and strength training was effective and resulted in improved metabolic control of DM compared with standard treatment. Despite significant cardiovascular risk reduction, conduit arterial elasticity did not improve.

Apolipoprotein E polymorphism and carotid artery intima-media thickness in a random sample of middle-aged men

Genetic polymorphism of apolipoprotein E (apoE) is an important factor in the development of coronary artery disease but the results concerning apoE genotype and carotid artery atherosclerosis remain controversial. We investigated a random sample of 189 Finnish middle aged men (mean age 54 years, range 50-59) to assess the role of apoE in the process of carotid atherosclerosis. Intima-media thickness (IMT) of the carotid artery wall was measured at three standardised segments (common carotid artery, bifurcation and internal carotid artery) by B-mode ultrasonography. Overall mean IMT value was also calculated. The carriers of E3/2 (n=20) genotype had significantly lower (P<0.01) total cholesterol and LDL cholesterol concentrations than carriers of E3/3 genotype (n=109) or the E4 allele (n=60). ApoE polymorphism was associated with common carotid artery IMT (P=0.034) when adjusted for age and body-mass index (model 1). The carriers of E3/2 had on average 9% (95% CI 0.8-16%, P=0.028) lower common carotid IMT values than the carriers of E3/3. After further adjustment with LDL and HDL cholesterol, systolic blood pressure, lipoprotein (a), apolipoprotein B and pack-years of smoking (model 2) the association was not statistically significant. The overall mean IMT varied significantly with apoE genotype (P=0.03 for model 1 and P=0.07 for model 2), and it was also lowest in the carriers of E3/2 genotype. This suggests that apoE E3/2 genotype is a protective factor in the development of carotid artery atherosclerosis in randomly selected middle-aged men. The favourable effect might be mediated at least partly by the lowering effect of E3/2 genotype on serum cholesterol.

Reduced oxidized low-density lipoprotein after weight reduction in obese premenopausal women.

BACKGROUND: Several studies support the hypothesis that oxidation of low-density lipoprotein (LDL) promotes atherogenesis. Obesity is one of the risk factors of atherosclerosis, but it is not known whether obesity is related to LDL oxidation.OBJECTIVE AND DESIGN: We investigated the effect of weight reduction and subsequent weight maintenance program on LDL oxidation in 77 obese premenopausal women (BMI 29–46 kg/m2). Another group of seven obese women served as a control group. Oxidized LDL was measured as baseline concentration of conjugated dienes in LDL lipids (ox-LDL). The weight reduction was performed in 12 weeks, using a very-low-energy diet.RESULTS: The mean weight loss was 13 kg (92 vs 79 kg). During weight reduction, the concentration of LDL cholesterol decreased by 11%, the concentration of ox-LDL decreased by 40%, and the ratio of ox-LDL to LDL by 33%. The concentration of LDL antioxidant capacity (LDL-TRAP) decreased by 8%, but the decrease was caused by the decrease in LDL. The concentration of LDL, ox-LDL or LDL-TRAP did not change in the control group. The weight reduction correlated with the decrease of ox-LDL. During the subsequent 9 month weight maintenance programme, the concentrations of serum LDL (10%), ox-LDL (11%), LDL-TRAP (29%), and the ratio of LDL-TRAP to LDL (21%) decreased.CONCLUSION: This study strengthens the evidence that the risk of atherogenesis is influenced favourably by weight reduction in obese women. This risk reduction is associated with a reduced oxidation of LDL.

Exercise training does not improve myocardial diastolic tissue velocities in Type 2 diabetes

BackgroundMyocardial diastolic tissue velocities are reduced already in newly onset Type 2 diabetes mellitus (T2D). Poor disease control may lead to left ventricular (LV) systolic dysfunction and heart failure. The aim of this study was to assess the effects of exercise training on myocardial diastolic function in T2D patients without ischemic heart disease.Methods48 men (52.3 ± 5.6 yrs) with T2D were randomized to supervised training four times a week and standard therapy (E), or standard treatment alone (C) for 12 months. Glycated hemoglobin (HbA1c), oxygen consumption (VO2max), and muscle strength (Sit-up) were measured. Tissue Doppler Imaging (TDI) was used to determine the average maximal mitral annular early (Ea) and late (Aa) diastolic as well as systolic (Sa) velocities, systolic strain (ε) and strain rate (έ) from the septum, and an estimation of left ventricular end diastolic pressure (E/Ea).ResultsExercise capacity (VO2max, E 32.0 to 34.7 vs. C 32.6 to 31.5 ml/kg/min, p = .001), muscle strength (E 12.7 to 18.3 times vs. C 14.6 to 14.7 times, p < .001), and HbA1c (E 8.2 to 7.5% vs. C 8.0 to 8.4%, p = .006) improved significantly in the exercise group compared to the controls (ANOVA). Systolic blood pressure decreased in the E group (E 144 to 138 mmHg vs. C 146 to 144 mmHg, p = .04). Contrary to risk factor changes diastolic long axis relaxation did not improve significantly, early diastolic velocity Ea from 8.1 to 7.9 cm/s for the E group vs. C 7.4 to 7.8 cm/s (p = .85, ANOVA). Likewise, after 12 months the mitral annular systolic velocity, systolic strain and strain rate, as well as E/Ea were unchanged.ConclusionExercise training improves endurance and muscle fitness in T2D, resulting in better glycemic control and reduced blood pressure. However, myocardial diastolic tissue velocities did not change significantly. Our data suggest that a much longer exercise intervention may be needed in order to reverse diastolic impairment in diabetics, if at all possible.

Vitamin D Receptor Alleles and Bone's Response to Physical Activity

Abstract. The objective of this prospective controlled study was to determine whether the osteogenic response of bone to mechanical loading is dependent on the vitamin D receptor (VDR) polymorphism. Thirty-five healthy premenopausal women took part in a progressive, high-impact exercise three times a week for a period of 18 months and 45 women served as nonexercising controls. The trainees were divided into three groups: bb (n = 12, 34%); Bb (n = 16, 46%); BB (n = 7, 20%) according to polymorphism at the gene encoding the VDR (BB representing subjects without the restriction enzyme BsmI sites on the two VDR gene alleles). Bone mineral content (BMC) and areal bone mineral density (BMD) were measured at the lumber spine, proximal femur, knee, calcaneus, and dominant distal radius before the beginning of the exercise regimen and at 12 and 18 months of training using dual-energy x-ray absorptiometry (DXA). As an indicator of the total osteogenic effect of the training, ΣBMC was derived by summing up the BMC values of the loaded sites (i.e., the lower limb sites and the lumbar spine). The mean ΣBMC increased 2.0% in the bb group, 3.0% in the Bb group, and 2.8% in the BB group (P= 0.184 for the intergroup difference), but only 0.8% in the controls (exercisers versus controls, P < 0.001). Individuals with the BB genotype of the VDR gene, subjects with whom the BMC can be lower than normal and whose bones can be less responsive to pharmacological therapies than bones of the other individuals, seem to have as good osteogenic response to mechanical loading as subjects with other VDR genotypes. Thus, irrespective of the VDR genotype, physical activity seems to be beneficial for bones of premenopausal women.

Successful weight maintenance preserves lower levels of oxidized LDL achieved by weight reduction in obese men.

Objective:We studied the association between weight maintenance, oxidized low-density lipoprotein (ox-LDL) and other lipoproteins in obese men.Methods:A 2-month weight reduction phase (WRP) with a very-low-energy diet was followed by a 6-month weight maintenance period and an unsupervised 2-year follow-up. Ninety men entered and 68 (76%) completed the study. Subjects were analyzed as one group and after division into two subgroups: 20 most successful men in maintaining the lost weight (subgroup 1) and the remaining (n=48) men (subgroup 2). Ox-LDL was measured by quantifying the amount of conjugated dienes in LDL particles.Results:The mean (±s.d.) weight reduction at the end of the WRP (n=68) was 14% (confidence interval (CI) 12.9–14.7%, 14.5±4.2 kg, P<0.001). Ox-LDL decreased by 22% (CI 16.9–28.1, 12.3±15.4 μmol/l, P<0.001). At the end of the 2-year follow-up, the regain in weight from the end of the WRP was 11% (CI 9.0–12.4, 9.6±6.2 kg, P<0.001). The regain in ox-LDL was 30% (CI 18.7–41.2, 8.2±15.4 μmol/l, P<0.001). In subgroup 1 vs 2, the respective regains were 3% (CI 0.9–4.2, 2.2±3.0 kg, P=0.006) vs 14% (CI 12.7–15.6, 12.9±4.0 kg, P<0.001) regarding weight and 9% (2.0±6.9 μmol/l, P=NS) vs 39% (CI 23.7–53.9, 11.2±17.2 μmol/l, P⩽0.001) in ox-LDL.Conclusion:The favorable changes seen in ox-LDL particles and serum lipids during weight reduction could be maintained by keeping the weight reduced, which may indicate decreased risk of atherosclerosis. But weight regain causes a resurge of ox-LDL.

Circulating oxidized low-density lipoprotein and common carotid artery intima-media thickness in a random sample of middle-aged men

Circulating oxidized low-density lipoprotein (oxLDL) has been suggested to play an important role in atherosclerosis development. According to previous observations, oxLDL correlates with clinically manifest coronary and carotid artery disease. We investigated the association between the oxLDL concentration measured directly in plasma and common carotid artery intima-media thickness (IMT) in a population-based, case-control study in middle-aged men from Southern Finland. oxLDL was determined in 214 men by a commercially available sandwich ELISA test (Mercodia). Carotid artery IMT was measured at 12 standardized segments by B-mode ultrasonography (at the near and far wall of the left and right common carotid arteries, bifurcations and internal carotid arteries), and the overall mean maximum IMT (MMaxIMT) was calculated. The MMaxIMT of the carotid arteries was significantly associated with circulating oxLDL (r(s) = 0.16, p = 0.018). In a stepwise multiple regression model with MMaxIMT as dependent variable and systolic blood pressure, smoking, oxLDL, HDL cholesterol and apolipoprotein B as covariates, systolic blood pressure (beta = 0.22, p < 0.001), oxLDL (beta = 0.15, p = 0.022) and smoking (beta = 0.17, p = 0.014) showed an independent association with IMT (R(2) = 0.10, p < 0.001). Our results show that oxLDL measured directly from plasma is independently associated with subclinical carotid artery atherosclerosis in middle-aged men.