Expropriation of "old order" mineral rights in South Africa: the Constitutional Court has its say (twice)

The Mineral and Petroleum Resources Development Act 28 of 2002 (ZA) (MPRDA) makes provision for the conversion of so-called “old order” rights to prospecting and mining rights. The consequences of the failure of holders of old order rights to apply for (a) Conversion or (b) new rights under different circumstances were decided by the South African Constitutional Court in two decisions during 2013. These cases are discussed against the background of the nature, content and termination of old order rights. It is also discussed whether such rights were expropriated by the MPRDA and, if so, whether compensation is payable by the state.

Supplement use among male university students

 Introduction and Aims: The aim of this study was to investigate patterns of supplement use among male university students, who have been identified as high consumers of these substances.

Design and Methods: An online survey investigating supplement use was conducted over four weeks. Participants were sent a link to the survey via email and through posts on the online homepages of units from the School of Exercise and Nutrition Sciences at Deakin University.

Results: Sixty-one males completed the survey (median age 21 years). All participants had used at least one supplement in their lifetime, with most having used legal supplements; the most commonly used supplement was sports drinks (80%), followed by protein (80%), and vitamins and minerals (80%). Although no participants reported use of anabolic-androgenic steroids, 18% would consider using them in the future. Motivations for use differed according to substance; for instance, vitamins and minerals were used for general health purposes while creatine was used to gain muscle. Friends were a common source of information about supplements (57%), followed by online (36%) and a supplement store staff member (22%). Participants reported few negative side effects from supplement use.

Discussion and Conclusions: Supplement use is common among this group, and some indicate intentions to use more serious substances such as steroids. This study presents valuable findings about supplement use habits and patterns among male university students. However, more research is needed among this population to determine whether body image and exercise habits can influence supplement use.

Poor agreement between self-reported diagnosis and bone mineral density results in the identification of osteoporosis.

Osteoporosis is a major health concern, estimated to affect millions worldwide. Bone mineral density (BMD) assessment is not practical for many large-scale epidemiological studies resulting in the reliance of self-report methods to ascertain diagnostic information. The aim of the study was to assess the validity of self-reported diagnosis of osteoporosis in a population-based study. This study examined data collected from 906 men and 843 women participating in the Geelong Osteoporosis Study. Osteoporosis was self-reported and compared against results of BMD scans of the hip and spine. Validity was examined by calculating sensitivity, specificity, positive predictive value, negative predictive value, and kappa statistic. Osteoporosis was self-reported by 118 (6.7%) participants and identified using BMD results for 64 (3.7%) participants. Specificity and negative predictive value were good (95.1% and 96.0%, respectively), whereas sensitivity and positive predictive value were poor (35.9% and 31.4%, respectively). The overall level of agreement (kappa) was 0.29. The results changed only slightly when we included participants with osteopenia and adult fracture as osteoporotic. Reliance on self-report methods to ascertain osteoporosis status is not recommended.

Life satisfaction and bone mineral density among postmenopausal women: cross-sectional and longitudinal associations

The purpose of this study was to determine whether and how global life satisfaction is associated with bone mineral density (BMD) and bone loss.

The association between major depressive disorder, use of antidepressants and bone mineral density (BMD) in men.

OBJECTIVE: Both depression and use of antidepressants have been negatively associated with bone mineral density (BMD) but mainly in studies among postmenopausal women. Therefore, the aim of this study was to investigate these relationships in men. METHODS: Between 2006 and 2011, 928 men (aged 24-98 years) from the Geelong Osteoporosis Study completed a comprehensive questionnaire, clinical measurements and had BMD assessments at the forearm, spine, total hip and total body. Major depressive disorder (MDD) was identified using a structured clinical interview (SCID-I/NP). The cross-sectional associations between BMD and both MDD and antidepressant use were analyzed using multivariable linear regression. RESULTS: Of the study population, 84 (9.1%) men had a single MDD episode, 50 (5.4%) had recurrent episodes and 65 (7.0%) were using antidepressants at the time of assessment. Following adjustments, recurrent MDD was associated with lower BMD at the forearm and total body (-6.5%, P=0.033 and -2.5%, P=0.033, respectively compared to men with no history of MDD), while single MDD episodes were associated with higher BMD at the total hip (+3.4%, P=0.030). Antidepressant use was associated with lower BMD only in lower-weight men (<75-110 kg depending on bone site). CONCLUSIONS: Both depression and use of antidepressants should be taken into account as possible risk factors for osteoporosis in men.

Muscle strength and areal bone mineral density at the hip in women: a cross-sectional study

BACKGROUND: Muscle strengthening exercises are promoted for building and maintaining a healthy skeleton. We aimed to investigate the relationship between muscle strength and areal bone mineral density (BMD) at the hip in women aged 26-97 years.

METHODS: This cross-sectional study utilises data from 863 women assessed for the Geelong Osteoporosis Study. Measures of hip flexor and abductor strength were made using a hand-held dynamometer (Nicholas Manual Muscle Tester). The maximal measure from three trials on each leg was used for analyses. BMD was measured at the hip using dual energy x-ray absorptiometry (DXA; Lunar DPX-L). Total lean mass, body fat mass and appendicular lean mass were determined from whole body DXA scans. Linear regression techniques were used with muscle strength as the independent variable and BMD as the dependent variable. Models were adjusted for age and indices of body composition.

RESULTS: Measures of age-adjusted hip flexor strength and hip abductor strength were positively associated with total hip BMD. For each standard deviation (SD) increase in hip flexor strength, the increase in mean total hip BMD (SD) was 10.4 % (p = 0.009). A similar pattern was observed for hip abductor strength, with an increase in mean total hip BMD of 22.8 % (p = 0.025). All associations between hip muscle strength and total hip BMD were independent of height, but were nullified after adjusting for appendicular lean mass or total lean mass.

CONCLUSIONS: There was a positive association observed between muscle strength and BMD at the hip. However, this association was explained by measures of lean mass.

Persisting side-to-side differences in bone mineral content, but not in muscle strength and tendon stiffness after anterior cruciate ligament reconstruction

Tendon stiffness may be involved in limiting peak musculoskeletal forces and thus may constitute an upper limit for bone strength. The patellar tendon bone (PTB) graft, which is harvested from the patellar tendon during surgical reconstruction of the anterior cruciate ligament (ACL), is an ideal scenario to test this hypothesis. Eleven participants were recruited who had undergone surgical reconstruction of the ACL with a PTB graft 1-10 years prior to study inclusion. As previously reported, there was no side-to-side difference in thigh muscle cross-sectional area, in maximum voluntary knee extension torque, or in patellar tendon stiffness, suggesting full recovery of musculature and tendon. However, in the present study bone mineral content (BMC), assessed by peripheral quantitative computed tomography, was lower on the operated side than on the control side in four regions studied (P = 0·0019). Differences were less pronounced in the two sites directly affected by the operation (patella and tibia epiphysis) when compared to the more remote sites. Moreover, significant side-to-side differences were found in BMC in the trabecular compartment in the femoral and tibial epiphysis (P = 0·004 and P = 0·047, respectively) with reductions on the operated side, but increased in the patella (P = 0·00016). Cortical BMC, by contrast, was lower on the operated side at all sites except the tibia epiphysis (P = 0·09). These findings suggest that impaired recovery of BMC following ACL reconstruction is not because of lack of recovery of knee extensor strength or patellar tendon stiffness. The responsible mechanisms still remain to be determined.

WISE-2005: bed-rest induced changes in bone mineral density in women during 60 days simulated microgravity

To better understand the effects of prolonged bed-rest in women, 24 healthy women aged 25 to 40 years participated in 60-days of strict 6° head-down tilt bed-rest (WISE-2005). Subjects were assigned to either a control group (CON, n=8) which performed no countermeasure, an exercise group (EXE, n=8) undertaking a combination of resistive and endurance training or a nutrition group (NUT, n=8), which received a high protein diet. Using peripheral quantitative computed tomography (pQCT) and dual X-ray absorptiometry (DXA), bone mineral density (BMD) changes at various sites, body-composition and lower-leg and forearm muscle cross-sectional area were measured up to 1-year after bed-rest. Bone loss was greatest at the distal tibia and proximal femur, though losses in trabecular density at the distal radius were also seen. Some of these bone losses remained statistically significant one-year after bed-rest. There was no statistically significant impediment of bone loss by either countermeasure in comparison to the control-group. The exercise countermeasure did, however, reduce muscle cross-sectional area and lean mass loss in the lower-limb and also resulted in a greater loss of fat mass whereas the nutrition countermeasure had no impact on these parameters. The findings suggest that regional differences in bone loss occur in women during prolonged bed-rest with incomplete recovery of this loss one-year after bed-rest. The countermeasures as implemented were not optimal in preventing bone loss during bed-rest and further development is required.