Biomedical subjects

Joonas Sirola

Publications and source records attributed to Joonas Sirola.

6 recordsLinked to original sources

PubMed2005

Associations between grip strength change and axial postmenopausal bone loss--a 10-year population-based follow-up study.

The aim of the present study was to investigate the associations between grip strength change and postmenopausal bone loss. The study population, 622 peri- and postmenopausal women, was a random sample of the OSTPRE-study cohort (n=13,100) in Kuopio, Finland. Bone mineral density (BMD) at the lumbar spine (LS) and femoral neck (FN) was measured with dual X-ray absorptiometry and grip strength with a pneumatic squeeze dynamometer at baseline in 1989-1991, at the 5-year follow-up in 1994-1997 and at the 10-year follow-up in 1999-2001. Women were divided into three groups according to the change in age-grouped grip strength quartile they belonged to in each measurement (n in 5-year/10-year follow-up): "decreased" (n=150/n=140), "maintained" (n=314/n=320) and "improved" (n=158/n=162). Women within the improved group had significantly lower bone loss at both FN and LS in comparison to the other two groups after 10 years of follow-up (P<0.01). Furthermore, in HRT non-users (n=305) the difference between the improved group and maintained group was only modest (P=0.04). In contrast, in HRT users (n=310) the mean annual BMD change among the improved group was positive (bone gain 0.11%/year) and differed significantly in comparison to modest bone loss in the decreased and maintained groups in both LS and FN (P<0.01). The linear trend between grip strength quartile change and LS/FN bone loss was significant in HRT users (P<0.001) in contrast to HRT non-users (P=NS) in the linear regression model. Any of these differences were not affected by adjustments for age, weight, height and other potential confounders. In conclusion, the present study suggests that improvement in age-grouped grip strength quartile is strongly associated with axial bone loss among postmenopausal women. This effect seemed to interact positively with estrogen repletion status. These results encourage performing further clinical studies on associations between muscle strength changes and bone loss.

Absorptiometry, Photon↗

PubMed2005

High bone mineral density among perimenopausal women.

Studies regarding high bone mineral density (HBMD) are few. In the population-based Kuopio Osteoporosis Risk Factor and Prevention Study, BMDs of women were measured from 1990-1991 and 1995-1997. The mean age of the 1,873 women studied was 53.5 years at baseline (range 48.0-59.6). In all, 248 women were excluded because of BMD measurement errors or artifacts: 41 from the HBMD group (20.6%) and 207 (12.4%) from the control group. The final study group consisted of 1,551 women, 168 in the HBMD group (baseline lumbar BMD >1.23 g/cm2; femoral BMD >1.01 g/cm2, and 5-year follow-up lumbar BMD >1.21 g/cm2; femoral BMD >0.98 g/cm2, respectively) and 1,383 in the control group. The predictors for HBMD in the multivariate regression analysis were as follows: hormone therapy (HT) during the follow-up from 0.5 to 2 years and for over 2 years (OR 2.06, CI: 1.11-3.81 and OR 2.16, CI 1.43-3.26) and being overweight (BMI from 25 kg/m2 to 30 kg/m2, and BMI >30 kg/m2) at baseline (OR 2.84, CI: 1.82-4.42; OR 5.94, CI: 3.47-10.16, respectively). High physical activity while 11-18 years of age was associated with HBMD (OR 1.69, CI: 1.17-2.45). Parity predicted HBMD so that after one to two births the OR was 2.66 (CI: 1.03-6.88) and 3.03 (CI: 1.16-7.90) after three or more births. Menopause was negatively associated with HBMD (OR 0.57, CI 0.38-0.85). There were more premenopausal women in the HBMD group (53.9 vs. 34.6%, P <0.001). The HBMD group showed fewer fractures. In conclusion, being overweight, parity, HT use, premenopause and high physical activity in adolescence seemed to be predictors for persistently high BMD in early postmenopausal women. We suggest that the fracture risk is low in these women, and thus they are neither primary candidates for BMD screening nor for osteoporosis medication.

Bone Density↗

PubMed2005

Muscle performance after the menopause.

The timing of the menopause transition has remained fairly constant throughout history. It represents a milestone in female health and, after passing through it, women experience increased musculoskeletal and cardiovascular morbidity. Muscle performance is an important determinant of functional capacity and quality of life among the elderly and is also involved in the maintenance of balance. Therefore, good muscle strength can prevent fragility fractures and lessen the burden of osteoporosis. Muscle strength begins to decline during the perimenopausal years and this phenomenon seems to be partly estrogen dependent. Randomized controlled trials have indicated that hormone replacement therapy may prevent a decline in muscle performance, although the exact mechanism of estrogen-dependent sarcopenia remains to be clarified. Exercises have been shown to improve postmenopausal muscle performance and hormone replacement therapy may also potentiate these beneficial effects. Improvement or maintenance of muscle strength alone, however, may not be considered as a primary indication for long-term hormone replacement therapy in view of current knowledge of its risks and benefits. Work history and educational background may be associated with postmenopausal muscle performance, which itself has unique associations with skeletal and cardiovascular diseases.

Aged↗

PubMed2004

Factors related to postmenopausal muscle performance: a cross-sectional population-based study.

The aim of the present study was to investigate cross-sectionally the association of postmenopausal muscle strength with simple performance tests. A random sample of 1,166 naturally postmenopausal women (born 1932-1941) was selected from the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort. Grip and quadriceps strength were measured with strain gauge dynamometers and reported in both absolute values (KPa and kg) and per kilogram of body mass (N cm(-2) kg(-1) and N kg(-1)). In addition, two performance tests, 'ability to stand on one foot' and 'ability to squat down to touch the floor' were carried out. A five-category self-assessment of overall health ('very good', 'good', 'moderate', 'bad', and 'very bad') was obtained by postal questionnaire. The women that were able to stand on one foot and able to squat down to touch the floor had greater grip and quadriceps strength than their counterparts ( P<0.001 and P<0.03 in ANOVA, respectively). In addition, self-assessed health had a strong positive association with muscle strength in the grip and leg extensor muscles in ANOVA ( P<0.001 between 'very good' and 'moderate' or poorer state of health) and regression model ( P<0.001). Adjustment for age, duration of menopause, body mass, height, physical activity level, use of HRT, and number of diseases and medications did not change any of the main effects. Also, there were no differences in results between absolute measurement values and values reported per kilogram of body mass. According to the present study, a simple performance test may be useful in the prediction of postmenopausal muscle strength. Furthermore, self-assessed state of health is strongly associated with muscle strength in postmenopausal women.

Body Constitution↗

PubMed2003

Factors affecting bone loss around menopause in women without HRT: a prospective study.

OBJECTIVES: The present study evaluated the effects of menopause and other putative bone loss modifying factors on bone mineral density (BMD) change. METHODS: The study population, 396 healthy women aged 48-59 years with no history of hormone replacement therapy (HRT) use or any bone affecting disease or medications, was selected from a random sample (n=2025) of the OSTPRE-study cohort (n=13100) in Kuopio, Finland. BMD at lumbar spine (LS) and three areas of proximal femur (femoral neck (FN), Ward's triangle (W), trochanter (T)) was measured with dual X-ray absorptiometry at baseline in 1989-1991 and at 5 years in 1994-1997. RESULTS: 116 women who reported the beginning of menopause during the follow-up (perimenopausal) had the greatest mean annual bone loss (-1.22%/year (LS), -0.87% year (FN), -1.14%/year (W), -0.36%/year (T)). In women under 5 years postmenopausal at baseline (early postmenopausal, n=172) bone loss rate was significantly lower than in perimenopausal women. In women over 5 years postmenopausal at baseline (late postmenopausal, n=108) bone loss rate was significantly further decreased only at lumbar spine. In peri- and postmenopausal women the annual BMD change was best described as a trinomial function of the duration of menopause at all sites (P<0.03). Of the life-style factors studied protective effects were found in weight increase in both spinal and femoral bone (P=0.010/P<0.001), high baseline weight in spine (P<0.001) and high grip strength in femoral neck (P=0.002). CONCLUSION: The beginning of menopause is accompanied by significant bone loss, which decreases in later menopause. Few other physiological and life-style factors were found to significantly contribute to this phenomenon.

Bone Density↗

PubMed2003

Smoking may impair the bone protective effects of nutritional calcium: a population-based approach.

Postmenopausal women were randomly selected to investigate the effects of smoking on prevention of bone loss with nutritional calcium. DXA was performed twice, and smoking and calcium intake habits were inquired through the mail in 954 women. Smoking dampened the bone protective effects of nutritional calcium. This may reflect the pathophysiology underlying smoking-induced bone loss postmenopause. This study evaluated the effect of smoking on the bone protective properties of nutritional calcium. Of the random sample of 954 peri- and postmenopausal women selected from the Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort (n = 13,100) in Kuopio, Finland, 182 had smoked at some time (ever smokers) and 772 had never smoked. Women were divided in tertiles according to self-reported dairy nutritional calcium intake (mg/day): < 648 (1st), 648-927 (2nd), > 927 (3rd). Bone mineral density at lumbar spine (LS) and femoral neck (FN) was measured with DXA at baseline in 1989-1991 and at the 5-year follow-up in 1994-1997. In a linear regression model, nutritional calcium intake did not predict annual bone loss in smokers. These results were similar in the subanalysis on 71 current smokers (at both baseline and 5-year measurements) and on 85 past smokers. In never smokers, a statistically significant linear trend was observed between calcium intake and annual bone loss at LS, but at FN only after adjustment for age, weight, hormone replacement therapy (HRT), and other covariates. In analysis of covariance (ANCOVA), no differences in bone loss rate were observed between calcium intake tertiles among smokers. In nonsmokers, the annual bone loss rate was lower in the second (-0.41%) and the third (-0.35%) tertile compared with the first tertile (-0.61%) at LS (p < 0.05) and lower in the third tertile (-0.55%) than in first tertile (-0.72%) at FN after adjustment for age, weight, HRT, and other covariates (p < 0.05). When smokers were added to the nonsmoker group, the differences in bone loss rate between calcium intake tertiles disappeared. In addition, in ANCOVA, the term of interaction between smoking and calcium intake was statistically significant at LS only. In conclusion, smoking seems to impair the bone protective effects of nutritional calcium in postmenopausal women, more clearly in LS than FN.

Bone Density↗