Bone mass in Parkinson's disease: a study with three methods

Bone health in Parkinson's disease: a systematic review and meta-analysis

OBJECTIVE

Parkinson's disease (PD) and osteoporosis are chronic diseases associated with increasing age. Single studies have reported associations between them and the major consequence, namely, increased risk of fractures. The aim of this systematic review and meta-analysis was to evaluate the relationship of PD with osteoporosis, bone mineral density (BMD) and fracture risk.

METHODS

A literature search was undertaken on 4 September 2012 using multiple indexing databases and relevant search terms. Articles were screened for suitability and data extracted where studies met inclusion criteria and were of sufficient quality. Data were combined using standard meta-analysis methods.

RESULTS

23 studies were used in the final analysis. PD patients were at higher risk of osteoporosis (OR 2.61; 95% CI 1.69 to 4.03) compared with healthy controls. Male patients had a lower risk for osteoporosis and osteopenia than female patients (OR 0.45; 95% CI 0.29 to 0.68). PD patients had lower hip, lumbar spine and femoral neck BMD levels compared with healthy controls; mean difference, -0.08, 95% CI -0.13 to -0.02 for femoral neck; -0.09, 95% CI -0.15 to -0.03 for lumbar spine; and -0.05, 95% CI -0.07 to -0.03 for total hip. PD patients were also at increased risk of fractures (OR 2.28; 95% CI 1.83 to 2.83).

CONCLUSIONS

This systematic review and meta-analysis demonstrate that PD patients are at higher risk for both osteoporosis and osteopenia compared with healthy controls, and that female patients are at greater risk than male patients. Patients with PD also have lower BMD and are at increased risk of fractures.

Parkinson disease and exercise

Parkinson disease (PD) is a progressive, neurodegenerative movement disorder. PD was originally attributed to neuronal loss within the substantia nigra pars compacta, and a concomitant loss of dopamine. PD is now thought to be a multisystem disorder that involves not only the dopaminergic system, but other neurotransmitter systems whose role may become more prominent as the disease progresses (189). PD is characterized by four cardinal symptoms, resting tremor, rigidity, bradykinesia, and postural instability, all of which are motor. However, PD also may include any combination of a myriad of nonmotor symptoms (195). Both motor and nonmotor symptoms may impact the ability of those with PD to participate in exercise and/or impact the effects of that exercise on those with PD. This article provides a comprehensive overview of PD, its symptoms and progression, and current treatments for PD. Among these treatments, exercise is currently at the forefront. People with PD retain the ability to participate in many forms of exercise and generally respond to exercise interventions similarly to age-matched subjects without PD. As such, exercise is currently an area receiving substantial research attention as investigators seek interventions that may modify the progression of the disease, perhaps through neuroprotective mechanisms.

Prevalence and risk factors of osteoporosis in patients with Parkinson's disease

Parkinson's disease (PD) is the most common cause of disability in the elderly. It is currently recognized as a cause of secondary osteoporosis. To evaluate the prevalence of osteoporosis in PD and detect its risk factors, 52 patients with PD (36 men/16 women) and 52 controls paired for age and sex were recruited. Clinical data including demography, disease duration and disease severity were collected. All subjects had bone mineral density (BMD) measured by dual energy X-ray absorptiometry, dorsal and lumbar spine X-ray, and biological exams (osteocalcin, CTX, parathormon). The mean age of the patients was 60.0 +/- 9.25 years [30-77], and the mean disease duration was 4.9 +/- 4.5 years [0.2-17]. Nine patients (17.3%) were osteoporotic and 28 (53.8%) osteopenic. BMD at the lumbar spine and the hip was lower among patients than controls (spine: 1.031 vs. 1.175 g/cm(2); P < 0.001; hip: 0.968 vs. 1.054; P = 0.02). PD patients with low BMD presented a more severe disease and an insufficient sun exposure and calcium intake. There was a positive statistically significant correlation between patients BMD and body mass index and negative correlation with age, severity of PD, and osteocalcin levels. The prevalence of osteoporosis/osteopenia is high in PD patients and seems related to the severity of the disease, an insufficient sun exposure and calcium intake. This osteoporosis constitutes with falls the major risk factors of fracture in PD patients.

Bone mineral density in patients with Parkinson's Disease

BACKGROUND AND AIMS

This study assesses bone mineral density (BMD) in the lumbar spine, proximal femur and hand, and examines the relationship between BMD and disease duration, Hoehn and Yahr staging in Turkish elderly patients with Parkinson's disease (PD).

DESIGN

Twenty-four PD patients and 31 age- and sex-matched controls took part in the study. The BMD in the lumbar spine (L2-L4), femoral neck, Ward's triangle, trochanter and bilateral hands were evaluated by dual X-ray absorptiometry (DXA).

RESULTS

There was no significant difference in right hand BMD (rHBMD), L2-L4 spinal BMD, and right proximal femur BMD between patients and controls. However, in female patients hand BMD and right femoral neck BMD were significantly lower than in female controls (p<0.05). Male patients had no significant difference in BMD measurements in any sites compared with controls. Patients' Hoehn and Yahr index and disease duration were negatively correlated with BMD in all sites except L2-L4.

CONCLUSIONS

We emphasize the increased risk for osteoporosis in elderly female patients with PD, which is more prominent in proximal femur and hand measurements. Elderly female patients should be carefully examined and screened for osteoporosis to prevent bone loss and associated disability.

A pilot study on the impact of body composition on bone and mineral metabolism in Parkinson's disease

The impact of body composition on bone and mineral metabolism in Parkinson's disease (PD) was evaluated. Body fat mass, lean mass, bone mineral content, and bone mineral density (BMD) were measured by DXA in 22 PD patients and 104 controls. Female patients exhibited reduced body mass index, fat mass, and BMD compared to controls (p<0.05). Significant positive correlation was found between 25 OHD levels and BMC. Diminished bone mass in women with PD was found to be associated with alterations in body composition and low 25 OHD levels.

Bone Mineral Density in Hip-Fracture Patients With Parkinson’s Disease: A Case-Control Study

OBJECTIVE

To investigate bone mineral density (BMD) levels in patients with Parkinson's disease (PD) who sustained a hip fracture.

DESIGN

Case-control study.

SETTING

Rehabilitation hospital in Italy.

PARTICIPANTS

We investigated 831 out of 887 white patients consecutively admitted to a rehabilitation hospital because of an original hip fracture resulting from a fall. Twenty-eight (3.37%) of the 831 patients were affected by PD. Twenty-eight controls matched for sex, age, and hip-fracture type (cervical or trochanteric) were found among the 803 non-PD patients.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

BMD was assessed by dual-energy x-ray absorptiometry (DXA) at the unfractured femur. Five sites were investigated in each subject: total proximal femur, femoral neck, trochanter, intertrochanteric area, and Ward's triangle. DXA scan was performed a mean +/- standard deviation of 22.2 +/- 7.8 days after fracture occurrence in the 28 patients and 22.0 +/- 5.3 days after fracture occurrence in the 28 controls.

RESULTS

BMD expressed as a T score did not differ significantly between the 28 PD patients and the 28 controls, whereas z score in the PD patients was significantly lower than 0 +/- 1 in the age- and sex-matched general population at 4 of the 5 sites of BMD assessment.

CONCLUSIONS

A sample of PD fallers who sustained a hip fracture had femoral BMD levels similar to those found in matched hip-fracture fallers who did not suffer from PD and significantly lower than those found in the matched reference population.

Osteoporosis in Parkinson's disease

There are few studies of osteoporosis in Parkinson's disease (PD). We assessed the prevalence of osteoporosis in a PD clinic cohort. All subjects with a confirmed diagnosis of PD attending a clinic were invited to participate. All consenting subjects had bone density measured by dual energy X-ray absorptiometry scanning. Further data, including demography, disease duration, and disease severity, were collected. One hundred five subjects participated; median age was 75 (54-92) years. Fifty-one (49%) patients were men. Of the men: median T score, -1.3 (range, -4.7 to 3.8); median Z score, 0.0 (-3.2 to 4.7); diagnostic categories: osteoporosis, 20%; osteopenia, 41%; normal, 39%. Of the women: median T score -2.7 (-4.7 to 1.4); median Z score, -0.25 (-2.6 to 4.2); diagnostic categories: osteoporosis, 63%; osteopenia, 28%; and normal, 9%. Whole sample: osteoporosis, 42%; osteopenia, 34%; and normal, 24%. There were associations between age, depression, disease duration, and osteoporosis but not with disease severity. Female gender was an independent predictor of osteoporosis. The prevalence of osteoporosis/osteopenia is considerable in PD patients but does not exceed that of other people of similar age. Osteoporosis/osteopenia was present in almost all women of this age group with PD.

Fracture risk after the diagnosis of Parkinson's disease: Influence of concomitant dementia

In an inception cohort of 196 Olmsted County, Minnesota, residents with Parkinson's disease (PD) first recognized in 1976 to 1995, we tested whether the increased risk of bone fractures is associated with concomitant dementia. Using the data resources of the Rochester Epidemiology Project, information about PD, dementia, other clinical risk factors for fracture and fracture events was obtained from review of complete inpatient and outpatient medical records spanning each subject's residence in the community. Compared to an equal number of age- and sex-matched non-PD referent subjects from the community, PD patients were at a 2.2-fold increased risk of fractures generally and a 3.2-fold greater risk of hip fractures specifically. Adjusting for age, the independent predictors of overall fracture risk in the PD subjects included female sex (hazard ratio [HR] 1.6; 95% confidence interval [CI], 1.1-2.3), dementia (HR, 1.6; 95% CI, 1.1-2.4) and chronic depression, which was associated with a reduced risk (HR, 0.4; 95% CI, 0.2-0.8). Hip fractures were predicted by dementia (HR, 2.2; 95% CI, 1.2-4.1). The increased fracture risk in patients with PD is not entirely explained by concomitant dementia, and additional study is needed to determine the relative contributions to fracture risk of falls versus bone loss in these patients.

Abnormal bone and calcium metabolism in patients after stroke

OBJECTIVE

To review how mineral stores and endocrine factors affect bone mass in poststroke patients immobilized by hemiparesis.

DATA SOURCES

Computer databases and published indexes.

STUDY SELECTION

Case-control studies of hemiparetic poststroke patients examined regarding bone metabolism.

DATA EXTRACTION

References were obtained from MEDLINE; all data concerning the objective were used.

DATA SYNTHESIS

Bone loss occurs in affected extremities after stroke. Immobilization from hemiplegia causes hypercalcemia. Insufficiency or deficiency of 25-hydroxyvitamin D (25-OHD) is very common in stroke patients and may be caused by poor dietary intake, decreased sunlight exposure, or both. Compensatory hyperparathyroidism may not occur because hypercalcemia inhibits the parathyroid glands even when 25-OHD is in the insufficient range. However, hyperparathyroidism does occur when 25-OHD is in the deficient range, in which case the parathyroid response to hypovitaminosis D overrides effects of hypercalcemia. Increased bone resorption was observed during the first year after stroke, declining to normal during the second year. During the first year, determinants of bone mineral density (BMD) in hands affected by hemiplegia were age, severity of hemiplegia, duration of paralysis, serum calcium concentration, and 25-OHD concentration. In the second year, BMD determinants on the hemiplegic side were severity of hemiplegia and 25-OHD concentration, whereas 25-OHD concentration was the only BMD determinant on the intact side. Administering 1alpha-hydroxyvitamin D3, vitamin K2, or ipriflavone ameliorated osteopenia on both sides and decreased the frequency of hip fracture on the hemiplegic side.

CONCLUSIONS

Bone remodeling and determinants of bone mass for the affected and unaffected sides after stroke differ between the first and subsequent years.

Secondary osteoporosis

Generalized osteoporosis currently represents a heterogeneous group of conditions with many different causes and pathogenetic mechanisms, that often are variably associated. The term "secondary" is applied to all patients with osteoporosis in whom the identifiable causal factors are other than menopause and aging. In this heterogeneous group of conditions, produced by many different pathogenetic mechanisms, a negative bone balance may be variably associated with low, normal or increased bone remodeling states. A consistent group of secondary osteoporosis is related to endocrinological or iatrogenic causes. Exogenous hypercortisolism may be considered an important risk factor for secondary osteoporosis in the community, and probably glucocorticoid-induced osteoporosis is the most common type of secondary osteoporosis. Supraphysiological doses of corticosteroids cause two abnormalities in bone metabolism: a relative increase in bone resorption, and a relative reduction in bone formation. Bone loss, mostly of trabecular bone, with its resultant fractures is the most incapacitating consequence of osteoporosis. The estimated incidence of fractures in patients prescribed corticosteroid is 30% to 50%. Osteoporosis is considered one of the potentially serious side effects of heparin therapy. The occurrence of heparin-induced osteoporosis appeared to be strictly related to the length of treatment (over 4-5 months), and the dosage (15,000 U or more daily), but the pathogenesis is poorly understood. It has been suggested that heparin could cause an increase in bone resorption by increasing the number of differentiated osteoclasts, and by enhancing the activity of individual osteoclasts. Hyperthyroidism is frequently associated with loss of trabecular and cortical bone; the enhanced bone turnover that develops in thyrotoxicosis is characterized by an increase in the number of osteoclasts and resorption sites, and an increase in the ratio of resorptive to formative bone surfaces, with the net result of bone loss. Despite these findings, the occurrence of pathological fractures in patients with hyperthyroidism is relatively low, and probably due to the fact that deficiencies in bone mass may be reversed by treatment of the thyroid disease. Most, but not all, studies on insulin-dependent diabetes mellitus (IDDM) report an association with osteopenia. In IDDM, the extent of bone loss is usually slight, which helps explain the discrepancy between the frequency of decreased bone mineral density, and the frequency of osteoporotic fractures in long-standing diabetes. Contradictory results have been obtained in non-insulin-dependent diabetes mellitus (NIDDM) patients. Increased rates of bone loss at the radius and lumbar spine were demonstrated either in patients with two-thirds gastric resection and Billroth II reconstruction, or in those with one-third resection and Billroth I anastomosis, and the metabolic bone disease following gastrectomy may consist also of osteomalacia or mixed pattern of osteoporosis-osteomalacia, with secondary hyperparathyroidism. Miscellaneous causes of secondary osteoporosis are also immobilization, pregnancy and lactation, and alcohol abuse.

Water bath and contact methods in ultrasonic evaluation of bone

Ultrasonic devices for the measurement of speed of sound (SOS) and broadband ultrasonic attenuation (BUA) generally use either a contact or water bath method. The aim of this study was to compare these two methods while determining the influence of soft tissue, pathlength (heel width and bone width), and a fixed heel dimension on SOS (m/second) and BUA (dB/MHz). Ultrasonic measurements were made using a CUBA Research system utilizing a pair of 1 MHz unfocused transducers with mean precision CV = 0.7% and 6.0% for all SOS and BUA measurements, respectively. SOS and BUA were determined in 24 human cadaveric heels under three conditions: contact method (heel intact), water bath method (heel intact), water bath method (no soft tissue). Although there were significant differences between measurements using contact and water bath techniques (heel intact), their correlations were high (r = 0.858 for SOS and r = 0. 937 for BUA; P < 0.001). After removal of soft tissue, SOS significantly increased (78 m/second; P < 0.001) whereas there was no change in BUA (P > 0.05). Heel width correlated with SOS measurements (-0.224 < r < -0.347; P < 0.001) and bone width correlated with BUA measurements (0.198 < r < 0.276; P < 0.001). The practice of using a fixed heel dimension (Lunar Achilles) was investigated by comparing SOS calculated with measured heel thickness and a value of 4 cm (Lunar Achilles). SOS increased by 42 m/second (2.7%) using the fixed heel dimension compared with measured heel widths. This study demonstrates the similarity between contact and water bath-based methods, while showing that the presence of soft tissue reduces SOS but has no effect on BUA. The use of a fixed heel dimension for calculation of SOS overestimates values obtained when using measured heel dimensions, though the values correlate highly (r = 0.98, P < 0.001). In addition, an increase in heel width tends to cause an underestimation of SOS whereas an increase in bone width tends to overestimate BUA, although the effects are relatively small.