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Biomedical subjects

O J Heinonen

Publications and source records attributed to O J Heinonen.

At least 19 recordsLinked to original sources
PubMed2007

The reduction of physical activity reflects on the bone mass among young females: a follow-up study of 142 adolescent girls.

UNLABELLED: Maintenance of positive effects of physical activity on growing bone is unknown. Physical activity was associated with increased BMC and BMD in a 7-year follow-up with 142 adolescent girls. Marked reduction in physical activity had an unfavorable effect on bone measurements, which is an important finding when the prevention of osteoporosis is considered. INTRODUCTION: Environmental factors influence quality and durability of bone. Physical activity, with high-impact weight bearing activity during puberty in particular, has been shown to have a beneficial effect on growing bone. Only few studies have been published on the maintenance of these effects. METHODS: At baseline, 142 girls aged 9-15 years participated in the present 7-year follow-up study. Growth and development, physical activity, and intakes of calcium and vitamin-D were recorded at intervals. BMC and BMD measurements were repeated using DXA. Based on the recording of physical activity during the follow-up measurements, the effect of the reduction in physical activity was examined with the bone measurements, and the measurements in the tertiles based on the amount of physical activity during the whole follow-up period were compared. RESULTS: Physical activity was positively associated with the development of BMC and BMD during the follow-up. The mean BMC of the lumbar spine increased 1.69 g (3%) (p = 0.021) more among those girls who maintained the physical activity level as compared with those who reduced it during last 4 years. In the femoral neck, the corresponding difference was 0.14 g (4.6%) (p = 0.015) between the same two groups of girls. The mean increases in BMC at lumbar spine and femoral neck were more substantial among those girls having the highest physical activity levels during the 7-year follow-up (46.7% and 22.6%) as compared with those having the lowest physical activity levels (43.3% and 17.4%, respectively). CONCLUSIONS: The findings of the present study show that regular physical activity is valuable in preserving the peak bone mass acquired at puberty in particular. Many of the girls who markedly reduced their activity levels lost bone in their femoral neck prior to their 25th birthday.

Absorptiometry, Photon↗
PubMed2006

Leisure-time physical activity of 13-year-old adolescents.

The leisure-time physical activity of 13-year-old Finnish adolescents was assessed in the prospective STRIP study. A self-administered questionnaire (N=565) was used. The leisure-time physical activity index (PAI; MET h/week) was calculated on the basis of reported exercise intensity, duration and frequency (N=558; 53% boys). The participants were divided into Sedentary, Moderately Active and Active groups by PAI tertiles. A subpopulation (N=197) also used a heart rate monitor (3 days, >/=8 h/day) to assess the time spent on different activity intensities. The median male PAI was 31.3 (inter-quartile range (IQR) 44.2) MET h/week and female 19.5 (IQR 26.3) MET h/week (P=0.0002). The cutoff points of the PAI tertiles were similar for the Active girls (31.3 MET h/week) and boys (32.6 MET h/week), but for the Sedentary boys it was 19.5 MET h/week and only 5.0 MET h/week for the Sedentary girls. High self-reported leisure-time physical activity associated poorly with time spent on moderate or vigorous exercise measured by heart rate monitoring. Active mothers had more often Active daughters or sons. In conclusion, the amount of leisure-time physical activity of one-third of 13-year-old girls is extremely low. Sedentary adolescents, especially girls, should therefore be put into focus for active efforts to increase their leisure-time physical activity. Parental models may be important.

Adolescent↗
PubMed2006

Association of reduced physical activity and quantitative ultrasound measurements: a 6-year follow-up study of adolescent girls.

Sonographic parameters of the heel were recorded in order to investigate the effects of changes in physical activities among 140 healthy growing peripubertal Caucasian girls. Calcaneal quantitative ultrasound measurements (Hologic Sahara) were recorded at baseline and 2- and 6-year follow-up. Broadband ultrasound attenuation, speed of sound (SOS), and T scores were documented. Altogether, 30 girls reduced their physical activity by >50% and 29 girls by 25-50%, whereas 81 girls continued at the present level or increased it. Age and physical activity together accounted for 16.7% of the variation in calcaneal T scores at baseline and for 16.4% at 2-year follow-up, whereas physical activity alone accounted for 11.3% of the variation at 6-year follow-up. The reduction in mean T scores was significant (from 2.0 to 0.8, P < 0.001) among those having discontinued their physical activity by the 6-year measurement. The changes between three groups were statistically significantly different from each other (P = 0.003). The mean SOS values decreased 16.78 meters per second (95% CI -26.9 to -6.7) among those having discontinued their physical activity between the 2- and 6-year follow-up measurements. The SOS value sensitively reacts to changes in physical activity, and consequently, it will help assess changes in bone quality. Because of such an immediate reaction, SOS is a good-quality measure for the physical condition of bone in young people and a suitable tool for detecting changes in calcaneal bone.

Adolescent↗
PubMed2006

Muscle fiber type I influences lipid oxidation during low-intensity exercise in moderately active middle-aged men.

The simultaneous effects of body composition, cardiorespiratory fitness, physical activity, and muscle fiber characteristics on lipid oxidation at basal state and during exercise were studied in a population-based group (n = 70) of middle-aged men. Body composition, oxygen uptake, and lipid oxidation were determined in a volitional maximal exercise test, physical activity with a questionnaire, muscle fiber characteristics with muscle biopsy, and resting metabolic rate and lipid oxidation at basal state with indirect calorimetry. In regression analysis, type I muscle fibers contributed significantly to lipid oxidation at basal state (r = 0.30, r2 = 0.07, P<0.05) and during low-intensity exercise (r = 0.35, r2 = 0.10, P<0.05). ANOVA revealed 7.7% (P = 0.268) lower lipid oxidation at basal state, 14% (P<0.05) lower lipid oxidation in low-intensity exercise, and 10.5% (P = 0.088) lower lipid oxidation in moderate-intensity exercise in muscle fiber tertile I (type I muscle fiber count 28.8%) compared with muscle fiber tertile III (type I muscle fiber count 71.4%). In conclusion, the muscle fiber distribution contributed significantly to lipid oxidation during low-intensity exercise in moderately active middle-aged men.

Analysis of Variance↗
PubMed2002

Peripheral nervous system in gyrate atrophy of the choroid and retina with hyperornithinemia.

OBJECTIVE: To evaluate peripheral nervous system involvement in gyrate atrophy of the choroid and retina with hyperornithinemia (GA). BACKGROUND: GA is an inborn error of amino acid metabolism caused by mutations in the enzyme ornithine aminotransferase. Patients with GA have hyperornithinemia, progressive centripetal loss of vision, minor CNS abnormalities, and type II muscle fiber atrophy with accumulation of tubular aggregates. The authors previously showed that muscle and brain creatine stores are depleted in the patients with GA. METHODS: The authors searched evidence of peripheral nervous involvement in 40 patients with GA (mean age 31.6 +/- 16.3 years; range 5 to 74 years) by using neurography, quantitative sensory threshold testing, and evoked potential testing. RESULTS: Neurography revealed abnormalities in 21 (53%) of the patients. The abnormalities associated with the severity of the ophthalmologic changes and the age of the patients. With quantitative sensory threshold testing, abnormal large-fiber function was found in seven (18%) and abnormal small-fiber function was found in four (10%) patients. Somatosensory evoked potential and brainstem auditory evoked potential responses were abolished in five patients. CONCLUSIONS: These findings of peripheral nervous system involvement in GA suggest that GA is a systemic disease affecting not only CNS but also the peripheral nervous system.

Adolescent↗
PubMed2001

Influence of physical activity and cessation of training on calcaneal quantitative ultrasound measurements in peripubertal girls: a 1-year prospective study.

The aim of this 1-year follow-up study was to investigate the influence of physical activity and cessation of competitive training on the changes in the sonographic parameters among healthy peripubertal girls. We used calcaneal quantitative ultrasound measurements. A total of 174 peripubertal Caucasian girls aged 11-17 years (61 gymnasts, 58 runners, and 55 nonathletic controls) were studied. Weight, height, stage of puberty, years of training, and the amount of leisure-time physical activity were recorded. Twenty-one sports participants (9 gymnasts, 12 runners) discontinued their training (retired) within 6 months from the baseline. The broadband ultrasound attenuation (BUA) and the sound of speed (SOS) through the calcaneus were recorded. The mean baseline BUA and SOS values of the nondominant calcaneus of the gymnasts were 11.9% (72.6 dB/MHz vs 64.9 dB/MHz, P < 0.05) and 2.0% (1600.4 m/s vs 1569.2 m/s, P < 0.001) higher than that of the controls, respectively. The baseline BUA and SOS values of the gymnasts and runners were similar. The mean 1-year increase in BUA was significant in the controls and sports participants who continued their training, whereas the change of BUA among the retired sports participants was not. The mean 1-year increases of SOS of the runners and controls were 6.6 m/s (95% CI 1.5 m/s to 11.7 m/s, P < 0.05) and 3.5 m/s (95% CI 0.5 m/s to 6.4 m/s, P < 0.05), respectively. In contrast, the SOS value among the retired runners declined and the 1-year change of SOS was -12.8 m/s (95% CI -22.1 m/s to -3.6 m/s, P < 0.05). The 1-year change of SOS among gymnasts was not significant. We conclude that the beneficial effect of exercise on the sonographic parameters of the calcaneus is evident but, at least partly, temporary. The SOS value decreases significantly soon after cessation of training and it may reflect the deterioration of the quantity and quality of bone without sufficient mechanical loading.

Adolescent↗
PubMed2001

Ophthalmologic heterogeneity in subjects with gyrate atrophy of choroid and retina harboring the L402P mutation of ornithine aminotransferase.

OBJECTIVE/PURPOSE: To investigate clinical variation in a genetically homogenous group of subjects with gyrate atrophy of choroid and retina with hyperornithinemia (GA). The group was made up of homozygotes and compound heterozygotes for mutation L402P in the ornithine aminotransferase (OAT) gene. DESIGN: Cross-sectional study. PARTICIPANTS: Thirty-five Finnish subjects (18 men) with GA with a mean age of 33 years (range, 5-74 years) carrying the Finnish founder mutation L402P. METHODS: All subjects were examined between 1993 and 1995. The analysis was composed of, in addition to careful clinical evaluation, studies of visual fields with Goldmann perimeter, photographing of the eye fundi, and corneal electroretinography (ERG) recordings. MAIN OUTCOME MEASURES: The changes in eye fundi, visual acuity, cataract changes in the lens, visual field constriction, and ERG responses were determined. RESULTS: Myopia, early cataracts, and highly abnormal ERG were typical for the GA subjects. The changes progressed rather uniformly with age. However, visual acuity, funduscopic findings, and visual fields showed great phenotypic variation. Despite the great interindividual variation, both eyes of each subject were always similarly affected. CONCLUSIONS: This study of 35 subjects with GA carrying a single mutation shows that the ophthalmologic symptoms and findings vary widely. The data also reveal that GA subjects are already affected by severe visual impairment in young adulthood. However, the diagnosis is often made very late.

Adolescent↗
PubMed2001

Effects of remobilization on rat femur are dose-dependent.

Seventy 9 to 11-week-old Sprague-Dawley male rats were divided into seven groups [baseline, 3-week, 11-week control groups; a group with a left limb immobilization for 3 weeks; and three groups with a similar immobilization and subsequent 8-week free (FR), low-intensity running (LR) or high-intensity running (HR) remobilization] to determine the site-specific effects of decreased mechanical loading and subsequent increased activity on rat femur. Bone mineral content of the proximal femur (PBMC), femoral midshaft (SBMC) and distal femur (DBMC) and the histomorphometry of the distal femur were used as outcome variables. The 3-week immobilization period resulted in significant bone loss in the proximal and distal ends of the immobilized left limb, the deficit being -5.9% in PBMC and -14.7% in DBMC. Immobilization also led to marked microarchitectural changes in the distal femur, the left-side deficit in trabecular bone volume (BV/TV) being -23.9%. After remobilization, there was a clear indication for dose-dependent response; i.e., immobilization-induced left-to-right side differences in BV/TV persisted in the FR animals (-23.8%), while these left limb deficits were significantly reduced in the LR group (-15.0%) and virtually absent in the HR group (-3.1%). The left limb deficit in PBMC was still significant in all groups after the 8-week period of remobilization [-9.6% in the FR group; -13.4% in the LR group; and -7.2% in the HR group]. The left-limb deficit in SBMC was significant in the HR11 group only (-7.2%), and, contrary to histomorphometric data, virtually absent in DBMC in all remobilization groups. As compared with the age-matched control data, the weight-adjusted BMCs of both limbs of the LR and HR groups were comparable or even higher (right limbs) than those of the controls. In conclusion, this study indicates that remobilization-induced bone recovery depends on the intensity of the remobilization so that during the 8-week period of remobilization, high-intensity running results in better recovery than low-intensity running, both of which are more efficient than free-cage activity only. Immobilization-induced changes in rat femur are also restored in a site-specific fashion, the most trabecular distal region of the femur showing more complete recovery than the more cortical proximal and midshaft regions.

Absorptiometry, Photon↗
PubMed2001

Lactate-transport activity in RBCs of trained and untrained individuals from four racing species.

In red blood cells (RBC) of horses, both lactate-transport activity and lactate accumulation during races vary interindividually. To study whether similar variation in lactate transport is apparent also in RBCs of other racing species, blood samples were collected from 21 reindeer, 40 horses, 31 humans, and 38 dogs. Total lactate-transport activity was measured at 10 and 30 mM concentrations, and the roles of the monocarboxylate-transporter (MCT) and the inorganic anion-exchange transporter (band-3 protein) were studied with inhibitors. In the reindeer and in one-third of the horses, lactate transport was low and mediated mainly by band-3 protein and nonionic diffusion. In the humans, dogs, and the remaining two-thirds of the horses, lactate transport was high and MCT was the main transporter. No correlation existed between MCT activity and the athleticism of the species. In the horses and humans, training had no effect on lactate transport, but in the reindeer and sled dogs, training increased total lactate transport. These results show that among the racing species studied, only in horses was the distribution of lactate-transport activity bimodal, and the possible connection between RBC lactate and performance capacity, especially in this species, warrants further studies.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2001

Peroneal tendon injuries. Report of thirty-eight operated cases.

BACKGROUND AND AIMS: Peroneal tendon injuries are probably frequently overlooked causes of lateral ankle pain after distorsion trauma. We report a series of 38 patients with peroneal tendon injuries and outcome after operation. MATERIAL AND METHODS: The mean age of the patients was 30 years (range, 13 to 61). All patients were operated by the same orthopaedic surgeon (SO) and the final outcome was evaluated. RESULTS: Eighty-two per cent of the patients were competitive athletes. There were 11 partial and 3 total ruptures of the peroneus brevis tendon (PBT), 2 partial and 2 total ruptures of the peroneus longus tendon (PLT). Nine cases of subluxations or luxations were treated. There were also 5 cases of chronic peroneal tendinitis or tenosynovitis, 5 cases of peroneal tendon anomalies and 1 ganglion. The peroneal tendon lesion was associated to ankle instability in 19 cases (50%). In ninety percent of the cases the result of the operation was excellent or good. CONCLUSIONS: The lateral ligaments are usually damaged in ankle distorsion injuries, but peroneal tendon lesions are often overlooked and probably more common cause of persistent lateral ankle pain than previously thought. Ruptures and luxations of the peroneal tendons need operative treatment in most cases.

Adolescent↗
PubMed2000

Influence of physical activity on ultrasound and dual-energy X-ray absorptiometry bone measurements in peripubertal girls: a cross-sectional study.

The aim of this cross-sectional study was to investigate whether two types of physical exercise affect the growing skeleton differently. We used calcaneal quantitative ultrasound measurements (QUS) and dual-energy X-ray absorptiometry (DXA) for measurement of bone mineral density (BMD), and to test how QUS values reflect the axial DXA values in these various study groups. A total of 184 peripubertal Caucasian girls aged 11-17 years (65 gymnasts, 63 runners, and 56 nonathletic controls) were studied. Weight, height, stage of puberty, years of training, and the amount of leisure-time physical activity were recorded. Broadband ultrasound attenuation (BUA) and sound of speed (SOS) through the calcaneus were measured. The BMD of the femoral neck and the lumbar spine were measured by DXA. The differences in mean values of bone measurements among each exercise group were more evident in pubertal than prepubertal girls. The mean BUA and SOS values of the pubertal gymnasts were 13.7% (77.8 dB/MHz versus 68.4 dB/MHz, P < 0.05) and 2.2% (1607.7 m/s versus 1572.4 m/s, P < 0.001) higher than of the controls, respectively. The mean BMD of the femoral neck in the pubertal gymnasts and runners was 20% (0.989 g/cm2 versus 0.824 g/cm2, P < 0.001) and 9.0% (0.901 g/cm2 versus 0.824 g/cm2, P < 0.05) higher than in the controls, respectively. The amount of physical activity correlated weakly but statistically significantly with all measured BMD and ultrasonographic values in the pubertal group (r = 0.19-0.35). The correlation between ultrasonographic parameters and BMD were weak, but significant among pubertal runners (r = 0.47-0.55) and controls (r = 0.39-0.42), whereas the DXA values of the femoral neck and the ultrasonographic parameters of the calcaneus did not correlate among highly physically active gymnasts. By stepwise regression analysis, physical activity accounted for much more of the variation in the DXA values than the ultrasonographic values. We conclude that the beneficial influence of exercise on bone status as measured by ultrasound and DXA was evident in these peripubertal girls. In highly active gymnasts the increase of the calcaneal ultrasonographic values did not reflect statistically significantly the BMD values of the femoral neck.

Absorptiometry, Photon↗
PubMed2000

Left ventricular mass, geometry and filling in elite female and male endurance athletes.

We compared echocardiographic findings in female (n=30) and male (n=30) endurance athletes to age-matched female (n=15) and male (n=15) sedentary controls. The differences between athletes and controls were similar in both sexes; only left ventricular (LV) mass and septum thickness differed slightly more in men than in women (67% vs 55%, P=0.004, and 36% vs 30%, P=0.03, respectively). LV wall thicknesses were in the normal range in all women, while four (13%) male athletes exceeded 13 mm. In conclusion, the effects of endurance training on echocardiographic findings appear to be quite similar in women and men. However, in female athletes with an abnormally thick left ventricular wall a thorough cardiac evaluation is indicated. This contrasts with male athletes, in whom LV wall thicknesses of over 13 mm are a not uncommon finding.

Adult↗
PubMed2000

Physical activity and bone mineral acquisition in peripubertal girls.

The association of the amount and type of physical activity with bone mineral acquisition was studied in 191 peripubertal Caucasian girls aged 9-16 years (66 gymnasts, 65 runners, and 60 nonathletic controls). Weight, height, stage of puberty, the amount of leisure-time physical activity, and years of training were recorded, and dietary calcium and vitamin D were assessed by a semi-quantitative questionnaire. The bone area, the bone mineral density (BMD), and the bone mineral content (BMC) of the femoral neck, lumbar spine and antebrachium were measured by dual-energy x-ray absorptiometry. The unadjusted mean values of BMD at the femoral neck were 15.2% higher in the pubertal gymnasts than in the controls (P<0.001). Compared with the controls, the mean BMC adjusted for bone area of the pubertal gymnasts at the femoral neck and lumbar spine was 16.4% and 10.8% higher, respectively. When comparing the association of the type of physical activity among the pubertal athletics by multiple regression analysis, height, physical activity, gymnastics, and Tanner stage emerged as significant variables and accounted for 54.7% and 63.4% of the total variation in BMD of the femoral neck and lumbar spine, respectively. These results indicate that physical activity is associated with bone mineral acquisition in peripubertal girls and that high-impact weight-bearing exercise seems to be particularly associated with the increase of the BMD at the femoral neck.

Adolescent↗
PubMed1999

Central nervous system involvement in gyrate atrophy of the choroid and retina with hyperornithinaemia.

In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), a genetically determined deficiency of ornithine delta-aminotransferase activity leads to high ornithine concentrations in body fluids. GA is characterized by centripetally progressing retinal and choroidal destruction and selective atrophy with tubular aggregates in type II skeletal muscle fibres. These findings have been suggested to be mediated by hyperornithinaemia-induced deficiency of high-energy creatine phosphate. As abnormal brain magnetic resonance images and electroencephalograms are found in another disorder of creatine metabolism, guanidinoacetate methyltransferase deficiency, we investigated the central nervous system involvement in GA, which seems to be associated with a milder degree of phosphocreatine deficiency. We compared 23 untreated GA patients with age-matched healthy controls, and with 9 patients who had received creatine or creatine precursor supplementation daily for several years. The mean age of the patients (32 +/- 18 years) was similar to that of the controls (36 +/- 22 years). The MRI or EEG findings of the patients on creatine supplementation did not differ from those of the untreated group. Brain MRI revealed degenerative lesions in the white matter in 50% of the GA patients, and 70% of the patients had premature atrophic changes, with a striking increase in the number of Virchow's spaces. Of the patients whose EEG was recorded, 58% had abnormal slow background activity, focal lesions or high-amplitude beta rhythm (> 50 microV). The EEG findings were not associated with the MRI changes or with the age or the sex of the patients. Early degenerative and atrophic brain changes and abnormal EEG are thus features of GA, in addition to the well-characterized eye and muscle manifestations.

Adolescent↗