Influence of muscle strength on bone strength during childhood and adolescence

In connection with the prevention of osteoporosis, paediatrics is challenged with ensuring the optimal formation of the skeletal system with maximal bone strength during childhood and youth. Biomechanical use represents the most important stimulus for activating the skeletal system. The measurement of muscle strength (grip strength) in 97 females aged 3-62 years and 71 males aged 3-61 years showed an age-dependent course. On the whole, males have greater strength with a more pronounced increase after puberty, reaching a peak maximum at 25-30 years. Females show a more moderate increase after puberty. In a pilot study, bone strength (as bone strength index-BSI) was analysed at the distal radius using peripheral quantitative computerized tomography (pQCT). BSI was calculated on the basis of the geometric data of the polar moment of resistance in combination with the cortical bone density. BSI values increase with age and reach a peak maximum at 25-30 years. There was a highly significant correlation between BSI and grip strength (r = 0.87). These relationships are especially interesting for therapeutic concepts differentiating between direct and indirect (via the muscle system) influences on the skeletal system. The non-invasive bone strength analysis in combination with muscle strength offer new perspectives for the evaluation of the functional muscle-bone unit.

The effect of a specific strength-development exercise on bone mineral density in perimenopausal and postmenopausal women

The objective of this study was to assess the effect of physical activity on bone density at the distal radius in healthy perimenopausal (23) and postmenopausal (60) women. The 83 women, aged 40-62 years, were randomized into two groups. The women participated in an exercise program of 40 minutes of jogging and 20 minutes of gymnastics three times a week for 1 year (group 1, n = 46) or 6 months (group 2, n = 37), respectively. Subjects in group 2 served as controls during the first 6 months. They were introduced to exercise classes after the first 6 months of the study and wore wrist weights (0.8 kg on each arm) during the gymnastics session. None of the women were on hormone replacement therapy (HRT). Results show a decrease in bone mineral density (BMD) during the first 6 months of the study in group 1 (2%, p < 0.01) and group 2, although this was not significant for the latter group (1.2%, n.s., p = 0.045). There was no significant change in osteocalcin serum concentration, fasting urinary calcium excretion, and calcium serum concentration during the first half of the study. After an additional 6 months, it was possible to stop BMD loss in both groups. Osteocalcin serum concentration significantly increased, and calcium serum concentration significantly decreased in groups 1 and 2. Fasting urinary calcium excretion decreased in both groups, although this was significant only in group 2 during the 1-year study. In conclusion, it proved possible to prevent BMD loss at the distal radius by our exercise program in perimenopausal and postmenopausal women. The effects of exercise may be general as well as localized. According to our results, additional localized benefits from a specific strength-development exercise may be seen.

Vitamin D receptor genotypes and changes of bone density in physically active German women with high calcium intake

Polymorphisms at the vitamin D receptor (VDR) gene have been reported to mediate important differences in bone mineral density (BMD) and bone metabolism. In this longitudinal study we examined the relationships between VDR genotypes and bone metabolism, changes in BMD and changes in ultrasound transmission velocity in a population of healthy unrelated German women. The study population comprised 50 physically active women (aged 43.3 to 62.8 years, 14 premenopausal, 36 postmenopausal) with a daily calcium intake of (mean +/- SD) 1045 +/- 338 mg, who had earlier participated in a longitudinal study on the association of physical activity and bone density and bone turnover. Each participant was genotyped for the BsmI polymorphism at the VDR gene locus. Markers of bone turnover (alkaline phosphatase, osteocalcin, procollagen type I C-terminal propeptide, collagen type I C-terminal telopeptide, tartrate-resistant acid phosphatase) were measured at baseline. BMD (determined by peripheral quantitative computed tomography at the distal radius) and ultrasound transmission velocity through bone (at calcaneus, patella and thumb) were analysed at baseline and 15 months later. The genotypic groups did not differ significantly (p > 0.05) in any of the parameters determined at baseline. Neither were there any differences between these groups in the changes of BMD or ultrasound transmission velocity during the study period. Thus, we conclude that in physically active German women with a relatively high calcium intake the impact of VDR genotypic polymorphisms on bone density, bone metabolism and changes in bone density may be of limited importance.

Anxiety disorders, depression and incontinence in preschool children-A population-based study

OBJECTIVE

The aim was to examine associations of specific anxiety disorders, depressive symptoms, and incontinence in a representative, population-based sample of preschool children.

METHODS

All preschool children of a defined geographical area examined before school-entry were included. Parents completed a questionnaire including the Preschool Feelings Checklist (PFC), eight questions referring to nocturnal enuresis (NE), daytime urinary incontinence (DUI), fecal incontinence (FI) and constipation, and 30 items regarding Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-5) diagnostic criteria of separation anxiety disorder (SAD), social phobia (SOC), specific phobia (PHOB), and generalized anxiety disorder (GAD). Data of 1206 children (mean age = 5.7 years; 53.5% boys) are presented.

RESULTS

34.6% of incontinent children had an anxiety disorder based on DSM-5 criteria and 13.3% had clinically relevant depressive symptoms (measured by the PFC). Rates of incontinence overall were 14.1% (11.9% NE, 3.1% DUI, and 1.8% FI) and 6.3% for constipation. Rates of SOC and PHOB were increased in NE (20.8% and 25.4%), DUI (39.3% and 34.5%) and FI (35.3% and 50.0%) compared to continent children (13.5% and 17.2%). Children with constipation had higher rates of SOC, PHOB, and GAD than those without. Compared to continent children (9.7%), depressive symptoms were more frequent in children with NE (26.8%), DUI (50.0%), and FI (61.9%).

CONCLUSION

Anxiety disorders and depressive symptoms are common in children with incontinence. The most specific DSM-5 disorders associated with incontinence are SOC and PHOB, which can be incapacitating and may require treatment. Due to the high rates of anxiety disorders, it is important to screen all children with incontinence, for example, with specific questionnaires.