Toni Rikkonen

University of Eastern Finland, Kuopio, Province of Eastern Finland, Finland

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Publications (26)75.82 Total impact

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    ABSTRACT: We examined the role of muscle strength, lean tissue distribution, and overall body composition as indicators of osteoporosis (OP) in a pooled sample of 979 Finnish postmenopausal women (mean age 68.1 years) from the Kuopio Osteoporosis Risk Factor and Prevention study. Bone mineral density (BMD) at the femoral neck (FN) and total body composition were assessed by dual-energy X-ray absorptiometry scans. The women (n = 979) were divided into three groups according to WHO criteria, based on FN BMD T score: normal (n = 474), osteopenia (n = 468), and OP (n = 37). Soft tissue proportions, fat mass index (FMI, fat/height²), lean mass index (LMI, lean/height²), and appendicular skeletal muscle mass (ASM, (arms + legs)/height²) were calculated. Handgrip and knee extension strength measurements were made. OP subjects had significantly smaller LMI (p = 0.001), ASM (p = 0.001), grip strength (p < 0.0001), and knee extension strength (p < 0.05) but not FMI (p > 0.05) compared to other subjects. Grip and knee extension strength were 19 and 16 % weaker in OP women compared to others, respectively. The area under the receiver operating characteristic curve was 69 % for grip and 71 % for knee extension strength. In tissue proportions only LMI showed predictive power (63 %, p = 0.016). An overall linear association of LMI (R² = 0.007, p = 0.01) and FMI (R² = 0.028, p < 0.001) with FN BMD remained significant. In the multivariate model, after adjusting for age, grip strength, leg extension strength, FMI, LMI, number of medications, alcohol consumption, current smoking, dietary calcium intake, and hormone therapy, grip strength (adjusted OR = 0.899, 95 % CI 0.84-0.97, p < 0.01), leg extension strength (OR = 0.998, 95 % CI 0.99-1, p < 0.05), and years of hormone therapy (OR = 0.905, 95 % CI 0.82-1, p < 0.05) remained as significant determinants of OP. Muscle strength tests, especially grip strength, serve as an independent and useful tool for postmenopausal OP risk assessment. In addition, lean mass contributes to OP in this age group. Muscle strength and lean mass should be considered separately since both are independently associated with postmenopausal BMD.
    Calcified Tissue International 06/2012; 91(2):131-8. · 2.50 Impact Factor
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    01/2012; , ISBN: 978-953-307-877-9
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    ABSTRACT: The aim of the present study was to investigate the health risks of excess body weight in the light of its protective effects on bone fragility. Femoral neck and lumbar spine dual X-ray absorptiometry was performed for 1970 Finnish women with a mean baseline age of 58.8 years (range 53.1-65.7 years) in 1994 and 2004. Women were categorized according to baseline BMI into normal <25 kg/m2, overweight 25-29.9 kg/m(2) and obese ≥30 kg/m(2). Weight change (kg) was categorized into tertiles. Co-morbidities, not allowed to be present at baseline, was based on self-reports. Osteoporosis was defined as femoral neck or spinal (L2-L4) T-score <-2.5 SD at 10-year follow-up or <-2.0 SD+low trauma energy follow-up fracture. Uni- and multivariate logistic regression models were used to estimate the 10-year risk of incident health disorders. Adjustment for age, number of diseases, alcohol intake and smoking was used in the multivariate models. Obesity (Ob) and overweight (Ow) were related with higher 10-year risk of hypertension (OR=2.6 (Ob)/OR=1.7 (Ow), p<0.001), coronary artery disease (OR=1.6, p<0.05/OR=1.2, p=NS), diabetes (OR=11.7/OR=5.3, p<0.001), osteoarthritis (OR=1.4, p<0.05/OR=1.1, p=NS), chronic back pain (OR=1.6, p=0.007/OR=1.2, p=NS) and poor self-rated health (OR=2.4, p<0.05/OR=1.5, p=NS) and lower risk of osteoporosis (OR=0.13/OR=0.28, p<0.001). Weight change of less than +1 kg was associated 1.8 and 2.6 times lower 10-year risk of having hypertension and breast cancer than weight change over 6.2 kg. Among obese women the absolute risk increase of hypertension was 17%, of diabetes 12%, and absolute risk reduction of osteoporosis 14% in comparison to BMI <25 kg/m(2). Health related risks of high BMI outweigh its protective effects on bone. Weight gain increases the risk hypertension and breast cancer.
    Maturitas 12/2011; 71(2):162-8. · 2.84 Impact Factor
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    ABSTRACT: About 75% of patients suffering from osteoporosis are not diagnosed. This study describes a multi-site bone ultrasound method for osteoporosis diagnostics. In comparison with axial dual energy X-ray absorptiometry (DXA), the ultrasound method showed good diagnostic performance and could discriminate fracture subjects among elderly females. Axial DXA, the gold standard diagnostic method for osteoporosis, predicts fractures only moderately. At present, no reliable diagnostic methods are available at the primary health care level. Here, a multi-site ultrasound method is proposed for osteoporosis diagnostics. Thirty elderly women were examined using the ultrasound backscatter measurements in proximal femur, proximal radius, proximal and distal tibia in vivo. First, we predicted the areal bone mineral density (BMD) at femoral neck by ultrasound measurements in tibia combined with specific subject characteristics (density index, DI) and, second, we tested the ability of ultrasound backscatter measurements at proximal femur to discriminate between individuals with previously fractured hips from those without fractures. Areal BMD was determined by axial DXA. Combined ultrasound parameters, cortical thickness at distal and proximal tibia, with age and weight of the subject, provided a significant estimate of BMD(neck) (r = 0.86, p < 0.001, n = 30). When inserted into FRAX (World Health Organization fracture risk assessment tool), the DI indicated the same treatment proposal as the BMD(neck) with 86% sensitivity and 100% specificity. The receiver operating characteristic analyses, with a combination of ultrasound parameters and patient characteristics, discriminated fracture subjects from the controls similarly as the model combining BMD(neck) and patient characteristics. For the first time, ultrasound backscatter measurements of proximal femur were conducted in vivo. The results indicate that ultrasound parameters, combined with patient characteristics, may provide a means for osteoporosis diagnostics.
    Osteoporosis International 06/2011; 23(4):1287-95. · 4.04 Impact Factor
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    01/2011; , ISBN: 979-953-307-269-1
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    ABSTRACT: The present study investigated the bone health related factors that were associated with the use of bisphosphonates (BP) among 2,050 postmenopausal Finnish women. Low BMD + low trauma energy fracture was the strongest determinant of BP use, while other secondary causes of osteoporosis were less strongly related with BP use. BP use was associated with reduced femoral neck (FN) and lumbar spine (LS) bone loss rate. The aim was to identify bone health related factors associated with the use of BP in a community setting. A population-based sample of 2,050 Finnish postmenopausal women was measured with dual X-ray absorptiometry at the FN and LS in 1989, 1994, 1999 and 2004, and information on osteoporosis risk factors, including low-trauma energy fractures, were collected with postal inquiries. Self-reported use of BP in 2004 was considered as the end point variable. Among BP users, 12% had T-score > -2.0 SD and no fracture during follow-up (FU). In women without any bone medication, 26% had T-score < -2.0 SD or low-trauma energy fracture or both during the FU. In BP users, a significant reduction in FN and LS bone loss rate, cumulative with duration of use, was observed in ANCOVA (p < 0.001). Among BP users, there was a significantly higher proportion of women with several independent risk factors for osteoporosis and more spine and humerus fractures but less ankle fractures. T-score < -2 SD combined with low-trauma energy fracture was significantly related to the use of BPs (p < 0.001, OR = 15.96) and T-score < -2 SD was a stronger predictor of BP use (p < 0.001, OR = 13.29) than fracture (p > 0.05, OR = 1.35) in multivariate logistic regression. Other factors related with BP use were vitamin D use (p = 0.001, OR = 2.27), high number of medications (p < 0.001, OR = 1.26) and rheumatoid arthritis (p < 0.05, OR 2.55). These findings reveal the recent bone health-related indications for BP prescription.
    Osteoporosis International 01/2011; 22(1):255-64. · 4.04 Impact Factor
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    ABSTRACT: Results on fracture risk among physically active persons are contradictory. The aim of this study was to investigate the long-term association between the self-reported physical activity (PA), the risk of fractures, and bone loss among peri- and postmenopausal women. The association between PA and fracture risk was examined during 15 years of follow-up in the population-based Osteoporosis Risk Factor and Prevention (OSTPRE) Study among 8560 women with a mean age of 52.2 years (range 47 to 56 years) at baseline. The amount and type of PA, as well as the types and mechanisms of fractures, were registered with self-administered questionnaires at 5-year intervals (ie, 1989, 1994, 1999, and 2004). A total of 2641 follow-up fractures were verified in 2073 women (24.2%). The study cohort was divided into quartiles by average hours of reported PA during the whole follow-up. Areal bone mineral density (aBMD) at the proximal femur (n = 2050) and lumbar spine (L(2)-L(4); n = 1417) was followed at 5-year intervals from a random stratified subsample with dual X-ray absorptiometry (DXA). Risk of fracture was estimated by using the Cox proportional hazards model with a mean follow-up time of 15.2 years. Weekly average time spent on leisure-time PA was 0.4, 1.7, 3.3, and 7.0 hours from the least to the most active quartiles, respectively. The risk of wrist fracture was higher in the active quartiles (II to IV) than in the most inactive quartile (I), with hazard ratios (HRs) of 1.3 [95% confidence interval (CI) 1.05-1.57, p = .014] for the second (II), 1.2 (95% CI 1.01-1.51, p = .045) for the third (III), and 1.4 (95% CI 1.14-1.69, p = .001) for the fourth (IV) quartile, respectively. Overall, most of the fractures were reported as a result of a fall (69.0%), with a 2.1 times higher rate of wrist fractures during the winter (November to April) than during summer season. There were no significant associations of PA with any other fracture types. Bone loss at the femoral neck, trochanter, and Ward's triangle was significantly associated with long-term PA (ANCOVA p < .05), whereas no associations of bone loss and PA in lumbar spine were seen. PA is associated with a moderate rise in wrist fracture risk, which might be explained in part by a higher number of outdoor activities. Regular PA of at least 1½ hours per week does not seem to increase the risk of other fractures and might significantly decrease proximal femur bone loss among peri- and postmenopausal women.
    Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 11/2010; 25(11):2332-40. · 6.04 Impact Factor
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    ABSTRACT: The hypothesis was that the calcium and vitamin D supplementation prevents falls at the population level.Study design: The OSTPRE-FPS was a randomized population-based open-trial with 3-year follow-up. The supplementation group (n=1566) received daily cholecalciferol 800IU+calcium carbonate 1000mg, while the control group (n=1573) received no supplementation or placebo. A randomly selected subsample of 593 subjects underwent a detailed measurement program including serum 25(OH)D measurements. The occurrence of falls was the primary outcome of the study. The participants in the subsample were telephoned at 4 months intervals and the rest of the trial population was interviewed by phone once a year. In the entire trial population (ETP), there were 812 women with 1832 falls in the intervention group and 833 women with 1944 falls in the control group (risk ratio was 0.98, 95% CI 0.92-1.05, P=0.160). The supplementation was not associated with single or multiple falls in the ETP. However, in the subsample, multiple fall incidence decreased by 30% (odds ratio (OR) 0.70, 95% CI 0.50-0.97, P=0.034) in the supplementation group. Further, the supplementation decreased the incidence of multiple falls requiring medical attention (OR 0.72, 95% CI 0.53-0.97, P=0.031) in the ETP. The mean compliance in the entire trial population was 78% and in the subsample 79%. Overall, the primary analysis showed no association between calcium and vitamin D supplementation and risk of falls. However, the results of a post hoc analysis suggested that there was a decreased risk of multiple falls requiring medical attention: this finding requires confirmation.
    Maturitas 04/2010; 65(4):359-65. · 2.84 Impact Factor
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    ABSTRACT: The Osteoporosis Risk Factor and Prevention-Fracture Prevention Study (OSTPRE-FPS) was a randomized population-based open trial (n = 593). The supplementation group (n = 287) received daily cholecalciferol 800 IU + calcium 1,000 mg for 3 years while the control group (n = 306) received neither supplementation nor placebo. Daily vitamin D and calcium supplementation have a positive effect on the skeleton in ambulatory postmenopausal women. vitamin D deficiency is common in the elderly, and vitamin D levels are associated with low bone mineral density (BMD). The working hypothesis was that vitamin D and calcium supplementation could prevent bone loss in ambulatory postmenopausal women. the OSTPRE-FPS was a randomized population-based open trial with a 3-year follow-up in 3,432 women (aged 66 to 71 years). A randomly selected subsample of 593 subjects underwent BMD measurements. The supplementation group (n = 287) received daily cholecalciferol 800 IU + calcium 1,000 mg for 3 years while the control group (n = 306) received neither supplementation nor placebo. in the intention-to-treat analysis, total body BMD (n = 362) increased significantly more in the intervention group than in the control group (0.84% vs. 0.19%, p = 0.011). The BMD change differences at the lumbar spine (p = 0.372), femoral neck (p = 0.188), trochanter (p = 0.085), and total proximal femur (p = 0.070) were statistically nonsignificant. Analyses in compliant women (≥ 80% of use) resulted in stronger and statistically significant effects at the total body and femoral regions. daily vitamin D and calcium supplementation have a positive effect on the skeleton in ambulatory postmenopausal women with adequate nutritional calcium intake.
    Osteoporosis International 03/2010; 21(12):2047-55. · 4.04 Impact Factor
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    ABSTRACT: Antifracture efficacy of high-dose vitamin D (800 IU) and calcium (1000 mg) remains controversial. To determine whether daily 800 IU of vitamin D and 1000 mg of calcium supplementation prevents fractures, we randomized 3432 women of the population-based Osteoporosis Risk Factor and Prevention (OSTPRE) Study cohort (ages 65 to 71 years) living in the region of northern Savonia, Finland (latitude 62 degrees to 64 degrees N) for 3 years to receive 800 IU of cholecalciferol and 1000 mg of calcium as calcium carbonate or to a control group that did not receive placebo. The main outcome measure was incident fractures. Fracture data were collected in telephone interviews and validated. Data on 3195 women, 1586 in the intervention group and 1609 in the control group, were available for analysis. In adjusted Cox proportional hazards models, the risk of any fracture decreased in the vitamin D and calcium group by 17% [adjusted hazard ratio (aHR) = 0.83; 95% confidence interval (CI) 0.61-1.12], and the risk of any nonvertebral fracture decreased by 13% (aHR = 0.87; 95% CI 0.63-1.19). The risk of distal forearm fractures decreased by 30% (aHR = 0.70; 95% CI 0.41-1.20), and the risk of any upper extremity fractures decreased by 25% (aHR = 0.75; 95% CI 0.49-1.16), whereas the risk of lower extremity fractures remained essentially equal (aHR = 1.02; 95% CI 0.58-1.80). None of these effects reached statistical significance. In conclusion, this study did not produce statistically significant evidence that vitamin D and calcium supplementation prevents fractures in a 65- to 71-year-old general population of postmenopausal women.
    Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 01/2010; 25(7):1487-95. · 6.04 Impact Factor
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    ABSTRACT: Aim was to investigate fracture risk (FR) according to bone loss (BL) rate. A random sample of 1652 women aged 53.5 years was measured with dual X-ray absorptiometry in femoral neck in 1989 and 1994 and divided into tertiles of annual BL rate: high >0.84%, moderate 0.13%-0.84%, and low <0.13%. Low trauma energy fractures during following 10 years were recorded. There were no differences in FR between BL tertiles in Cox regression model. Factors predicting lower FR in Cox model were in high tertile: high T-score (HR 0.71; 95% CI 0.54-0.93, P = .012), no sister's fracture (HR 0.35; 0.19-0.64, P = .001), no mother's fracture (HR 0.52; 0.31-0.88, P = .015), in moderate tertile: high T-score (HR 0.69;0.53-0.91, P = .008) and good grip strength (HR 0.98; 0.97-0.99, P = .022). In low tertile there were no predictors for FR. BL predicted FR in women with mother's fracture in univariate and multivariate model (OR 2.6; 1.15-5.7, P = .021) but with sister's fracture this was observed only in multivariate model (OR 2.66; 1.09-6.7, P = .039). Accordingly, the risk factors for postmenopausal fractures, especially mother's fracture, may interact with BL.
    Journal of osteoporosis. 01/2010; 2010:736391.
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    ABSTRACT: To investigate the correlates and predictors of self-rated health (SRH) and self-reported ambulatory status (AMB) among elderly women. A random sample of 1620 postmenopausal women aged 53-66 years in 1994 was selected from Osteoporosis Risk Factor and Prevention (OSTPRE) - study cohort in Finland. SRH and AMB were assessed in baseline (1994) and after 10-year follow-up (2004). A prognostic model was developed to predict the probability of good 10-year SRH and AMB. Full AMB was correlated with and predicted by good SRH (OR=4.3, p<0.001). Good quality of life (QoL) was both correlate and predictor of good 10-year SRH (OR=2.0, p<0.001) and full AMB (OR=2.6, p<0.001). Low BMI was associated with good SRH (OR=0.97, p<0.049) and full AMB (OR=0.92, p<0.001), good grip strength with good SRH (OR=2.7, p<0.001) and ability to squat down with full AMB (OR=1.7, p=0.002). Cardiovascular diseases, arthritis and back pain were common significant negative correlates (p<0.001) of baseline AMB and SRH out of variety of chronic diseases with significant association with either one. The significant (p<0.05) baseline predictors in final prognostic model for good 10-year SRH included baseline AMB and SRH, QoL, age, BMI, grip strength and psychiatric diseases (C-index=0.81) and for full 10-year AMB ability to squat, baseline AMB and SRH, QoL, BMI, hypertension and arthritis (C-index=0.81). These risk scores had better predictive power in comparison to that of baseline SRH and AMB alone (p<0.001 in univariate Z-score test). Among elderly women AMB is strongly linked to SRH. SRH and AMB are affected mostly by musculoskeletal, cardiovascular and psychiatric diseases as well as body anthropometry, muscle strength and subjective QoL. The present study provides a novel algorithm for predicting probability of full AMB and good SRH in postmenopausal women.
    Maturitas 12/2009; 65(3):244-52. · 2.84 Impact Factor
  • Bone 01/2009; 44. · 3.82 Impact Factor
  • Bone 01/2009; 44. · 3.82 Impact Factor
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    ABSTRACT: There is a need for cost-effective clinical methods to select women for bone densitometry. The aim of the present study was to determine whether relatively simple and clinically applicable physical tests could be useful in prediction of bone density in postmenopausal women. A total of 606 women (age range 66-71 years) taking part in the population based OSTPRE Fracture Prevention Study were investigated. Spinal and femoral bone mineral density (BMD) was measured by Dual X-ray Absorptiometry (DXA). Physical tests included the standing-on-one-foot (SOOF), grip strength (GS), leg extension strength, ability to squat down, standing 10 s eyes closed, chair rising, regular walk for 10 m and tandem walk for 6 m. All linear regression models were adjusted for age, body mass index, years on hormone therapy, years since menopause, current smoking and use of oral glucocorticoids. The SOOF was associated with lumbar spine BMD (r2=0.16, p=0.004) and the femoral regions (r2 values from 0.17 to 0.23 and p-values all<0.001). The GS was associated with lumbar spine BMD (r2=0.16, p=0.011) and the femoral regions (r2 values from 0.16 to 0.21 and p-values from <0.001 to 0.004). The ability to squat down on the floor was associated with the femoral regions (r2 values from 0.15 to 0.21 and p-values from 0.028 to 0.040). In addition, functional capacity was decreased in women with femoral neck osteoporosis (WHO classification) compared to women with normal or osteopenic BMD: SOOF -39% (p=0.001), GS -18% (p<0.001), leg extension strength -19% (p=0.007) and ability to squat down on the floor -40% (p=0.004). For osteoporosis prediction (ROC analysis) a threshold of a 22 kg in GS would yield a true-positive rate (sensitivity) of about 58% and a true-negative rate (specificity) of 86% (AUC 0.76). We suggest that grip strength could be used in medical decision making to identify those women who would benefit from BMD measurements albeit alone it may not provide accurate enough tool for osteoporosis screening.
    Bone 12/2008; 44(4):660-5. · 3.82 Impact Factor
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    ABSTRACT: Vitamin D is suggested to have a role in the coupling of bone resorption and formation. Compared with women, men are believed to have more stable bone remodeling, and thus, are considered less susceptible to the seasonal variation of calcitropic hormones. We examined whether seasonal variation exists in calcitropic hormones, bone remodeling markers, and BMD in healthy men. Furthermore, we determined which vitamin D intake is required to prevent this variation. Subjects (N = 48) were healthy white men 21-49 yr of age from the Helsinki area with a mean habitual dietary intake of vitamin D of 6.6 +/- 5.1 (SD) microg/d. This was a 6-mo double-blinded vitamin D intervention study, in which subjects were allocated to three groups of 20 microg (800 IU), 10 microg (400 IU), or placebo. Fasting blood samplings were collected six times for analyses of serum (S-)25(OH)D, iPTH, bone-specific alkaline phosphatase (BALP), and TRACP. Radial volumetric BMD (vBMD) was measured at the beginning and end of the study with pQCT. Wintertime variation was noted in S-25(OH)D, S-PTH, and S-TRACP (p < 0.001, p = 0.012, and p < 0.05, respectively) but not in S-BALP or vBMD in the placebo group. Supplementation inhibited the winter elevation of PTH (p = 0.035), decreased the S-BALP concentration (p < 0.05), but benefited cortical BMD (p = 0.09) only slightly. Healthy men are exposed to wintertime decrease in vitamin D status that impacts PTH concentration. Vitamin D supplementation improved vitamin D status and inhibited the winter elevation of PTH and also decreased BALP concentration. The ratio of TRACP to BALP shows the coupling of bone remodeling in a robust way. A stable ratio was observed among those retaining a stable PTH throughout the study. A daily intake of vitamin D in the range of 17.5-20 microg (700-800 IU) seems to be required to prevent winter seasonal increases in PTH and maintain stable bone turnover in young, healthy white men.
    Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 10/2008; 24(2):346-52. · 6.04 Impact Factor
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    ABSTRACT: This study of postmenopausal women (n=2,928) with an eight-year follow-up revealed that impairment in functional status associated with the increased fracture risk. The standing-on-one-foot and grip strength tests and a question about self-assessed ability to move can be used to identify women with a high risk of suffering a fracture. Poor functional status has pointed to associate with injurious falls and consequent fractures. Our aim was to define association between functional capacity and fractures. This study was based on the Osteoporosis Risk Factor and Prevention Study (OSTPRE). A total of 2,928 postmenopausal women took part in the functional capacity and muscle strength tests. The duration of fracture follow-up varied from 6.43 to 9.86 (mean 8.37) years and the first fracture was the end-point event for the statistical analyses. All analyses were done with Cox-regression. A total of 261 end-point fractures occurred. In multivariate analysis the inability to stand-on-one-foot for 10 seconds increased the risk of hip fracture (hazard ratio with 95% CI) 9.11-fold (1.98-42.00). Decreased grip strength associated with 1.05-fold (1.01-1.09) increased risk of hip fractures. Low leg extension strength associated with 1.02-fold (1.00-1.03) higher risk for all fractures. The self-assessed ability to walk less than 100 meters at baseline increased the risk of ankle 2.36-fold (1.10-5.08), hip 11.57-fold (2.73-49.15) and clinical vertebral fractures 3.85-fold (1.45-10.22). According to these results the standing-on-one-foot less than 10 seconds, grip strength and a question about ability to walk less than 100 meters may help to predict postmenopausal fractures.
    Osteoporosis International 09/2008; 19(8):1203-10. · 4.04 Impact Factor
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    ABSTRACT: Most bone ultrasound devices are designed for through-transmission measurements of the calcaneus. In principle, ultrasound backscattering measurements are possible at more typical fracture sites of the central skeleton. Unfortunately, soft tissue overlying the bones diminishes reliability of these measurements. To apply the single-transducer dual-frequency ultrasound (DFUS) technique to eliminate the errors induced by soft tissue on the measurements of integrated reflection coefficient (IRC) in human distal femur in vivo. Ultrasound and dual-energy X-ray absorptiometry (DXA) examinations were conducted on a bodybuilder during a 21-week training and dieting period. Significant changes in quantity and composition of soft tissue took place during the diet. However, DXA measurements showed no significant effects on bone density measurements. The single transducer DFUS technique enabled the determination of local soft-tissue composition, as verified by comparison with the DXA (r=0.91, n=8, p<0.01). Further, the technique eliminated the soft-tissue-induced error from IRC measured for the bone. The uncorrected IRC associated significantly with the change in local soft-tissue composition (r=-0.83, n=8, p<0.05), whereas the corrected IRC values showed no significant dependence (r=-0.30, n=8, p=0.46) on local soft-tissue composition. The DFUS technique may significantly enhance the accuracy of clinical ultrasound measurements of bone.
    Acta Radiologica 08/2008; 49(9):1038-41. · 1.33 Impact Factor
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    ABSTRACT: The aim of the present study was to investigate the ability of grip strength measurements to predict fracture risk in perimenopausal women according to bone mineral density (BMD). A random sample of 971 perimenopausal women from the Kuopio Osteoporosis Risk Factor and Prevention study cohort was measured with dual-energy X-ray absorptiometry (DXA) at the femoral neck and grip strength with a pneumatic squeeze dynamometer in 5-year intervals from baseline (1989-1991). Fractures during the 15-year follow-up were recorded based on self-reports and validated from medical records. In the total sample and in osteopenic or osteoporotic women (T score < -1, n = 284) grip strength was not significantly associated with fracture-free survival rate (P = nonsignificant in Cox regression). In women with normal baseline BMD (N-BMD, T score > -1, n = 687) the lowest grip strength quartile had a significantly lower fracture-free survival rate in the Cox proportional hazard model (P = 0.005, hazard ratio [HR] = 2.0). In the multivariate Cox regression model, T score and grip strength were the only significant predictors of 15-year fracture-free survival in the N-BMD group and a risk index (RI) was formed according to HRs of these two variables. High RI (0-5 points) was associated with significantly lower 15-year fracture-free survival rate (P = 0.001, HR = 0.137) in the N-BMD group. In contrast, 5-year T score was no better a predictor of fractures in the baseline N-BMD group (P = 0.04, HR = 0.36). In conclusion, grip strength predicts 15-year fracture-free survival in perimenopausal women with N-BMD, while 5-year DXA does not seem to be any better a predictor of fracture risk. DXA measurements could be coupled with simple and cost-effective grip strength measurements. Controlling BMD in women with N-BMD could be abandoned.
    Calcified Tissue International 08/2008; 83(2):93-100. · 2.50 Impact Factor
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    ABSTRACT: Soft tissues diminish reliability of the bone ultrasound backscatter measurements. In this study, the ability of a single broadband transducer dual frequency ultrasound (DFUS) technique to monitor the changes in soft tissue was investigated in a body builder during a 21 week training and dieting period, inducing a weight loss of 16.5 kg (18%). Then, DFUS was applied to correct the errors induced by soft tissues on the measurements of integrated reflection coefficient (IRC) in human distal femur. In DFUS, US reflection from soft tissue-bone interface is determined with two different US frequencies and, by knowing the frequency specific US attenuation and speed in adipose and lean tissues, their content can be determined. The dual energy X-ray absorptiometry (DXA) indicated that significant changes in quantity and composition of soft tissue, but not in bone density, took place during the diet. As compared with DXA, the single transducer DFUS could determine local soft tissue composition (r(2) = 0.88, n=8, p < 0.01). The change in uncorrected IRC associated significantly with the change in body composition (r(2) = 0.56, n=8, p < 0.05). The IRC values, corrected by DFUS, showed only minor variation (SD = +/- 1.26 dB) during the diet.
    The Journal of the Acoustical Society of America 06/2008; 123(5):3638. · 1.65 Impact Factor