Rheumatol Int (2008) 28:1205–1209 DOI 10.1007/s00296-008-0632-6
ORIGINAL PAPER
Prevalence and risk factors of osteoporosis in patients with Parkinson’s disease A. Bezza · Z. Ouzzif · H. Naji · L. Achemlal · A. Mounach · M. Nouijai · A. Bourazza · R. Mossadeq · A. El Maghraoui
Received: 6 January 2008 / Accepted: 14 June 2008 / Published online: 1 July 2008 © Springer-Verlag 2008
Abstract 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/cm2; P < 0.001; hip: 0.968 vs. 1.054; P = 0.02). PD patients with low BMD presented a more severe disease and an insuYcient sun exposure and calcium intake. There was a positive statistically signiWcant correlation between patients BMD and body mass index
A. Bezza · H. Naji · L. Achemlal · A. Mounach · M. Nouijai · A. El Maghraoui (&) Rheumatology and Physical Rehabilitation Centre, Military Hospital Mohammed V, PO Box: 1018, Rabat, Morocco e-mail:
[email protected] Z. Ouzzif Biochemistry Department, Military Hospital Mohammed V, PO Box: 1018, Rabat, Morocco A. Bourazza · R. Mossadeq Neurology Department, Military Hospital Mohammed V, PO Box: 1018, Rabat, Morocco
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 insuYcient sun exposure and calcium intake. This osteoporosis constitutes with falls the major risk factors of fracture in PD patients. Keywords Parkinson’s disease · Bone density · DXA · Osteoporosis · Osteopenia
Introduction Parkinson’s disease (PD) is a chronic, progressive neurodegenerative disorder characterized by tremor, muscular rigidity, slowness of movement, and postural imbalance. PD increases in prevalence with age, rising from 0.6% in those aged 65–69 years to nearly 3% in those older than 80. Recent advances in diagnosis and treatment have prolonged survival in elderly patients with Parkinson’s disease (PD). Consequently, recent reports [1–4] indicate a high incidence of hip fracture in PD patients, with falls being a major cause, especially in elderly females. Hip fractures are associated with more deaths, disability and medical costs than all other osteoporosis-related fractures combined [5]. Results from previous studies have demonstrated an association between PD and lower bone mineral density (BMD), which, if present, could aVect PD patients’ fracture risk independent of the risk attributable to falls [6–9]. However, few studies have evaluated bone turnover markers among patients with PD. The aim of this study was to assess the prevalence and risk factors associated with osteoporosis (OP) in patients with PD and to look for correlation with bone turnover parameters.
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Patients and methods Patients Participants in this study were 52 consecutive patients with idiopathic PD and attending the neurology department during a period of 7 months. All study participants signed the informed consent for any scientiWc approach to their medical registered data. Our institutional review board approved this study. A questionnaire collected information on life style, smoking habits, and level of physical activity in leisure time; calcium consumption, sunlight exposure and the use of vitamins and medications. Mean daily dietary calcium was calculated for each individual. Sunlight exposure was assessed by the patients or family members in terms of the preceding year, being graded as almost none, less than 15 min per week, or longer. Menstrual and reproductive history were assessed. Premenopausals were deWned as subjects having one or more menstrual bleedings during the last year. Postmenopausals were deWned as those who had their last menstrual period >1 year ago in accordance with clinical deWnitions of the WHO. PD severity were assessed using Hoehn and Yahr scale with stage 0 being no signs of PD, stage I: unilateral signs with no impairments for everyday activities; stage II: signs predominating on one side, with some impairment; stage III: bilateral signs with some postural instability (patient self-suYcient); stage IV: the patient is severely disabled but can walk (some loss of selfsuYciency); and stage V: the patient is conWned to a wheelchair or bed (not self-suYcient). Height and weight were measured in our centre before DXA measurement, in light indoor clothes without shoes. Body mass index (BMI) was calculated by dividing weight in kilograms by height in meters squared. Patients were excluded if they showed other known causes of osteoporosis, such as hyperparathyroidism or renal osteodystrophy, impairment of renal, cardiac, or thyroid functions; a history of therapy with corticosteroids, oestrogens, calcitonin, bisphosphonate, calcium, or vitamin D or its derivates.
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detectable diVerence of 0.04 g/cm2 (spine) and 0.02 (hips) [10, 11]. Patient BMD was measured at the lumbar spine (L1–4) (anteroposterior projection) and the femurs (dual femur). The mean result of the measure of the two femurs (total hip) was used. BMD values, expressed in g/cm2, were converted into T-scores, expressed in standard deviations (SDs), using Moroccan reference values for women [12]. For men, we used the reference values furnished by the constructor. We used the WHO classiWcation range to categorize subjects as normal (T > ¡1), osteopenic (¡2.5 < T · ¡1), or osteoporotic (T · ¡2.5). Biological assessment Biological and clinical assessments were performed on the same day. All samples were taken in the early morning. Blood was collected in vacutainers without additive. After centrifugation at 1,500 g for 10 min, serum was aliquoted and stored at ¡20°C. Serum concentrations of calcium, phosphorus, alkaline phosphatases were measured by standard methods. Serum osteocalcin, crosslaps (C-telopeptide, CTx), 1–84 parathyroid hormone were measured in 52 patients and 52 controls using electrochemiluminescence on an ELECSYS 2010 analyser (Roche Diagnostics, Mannheim, Germany). Controls The control group consisted of 52 healthy subjects. The controls were age- and sex-matched to the patients. The exclusion criteria were the same as the patients group. Statistical analysis This cross-sectional study was conducted in diVerent steps. The Wrst step consisted in the description of the study population. In the second step, we compared BMD data in patients and controls using Student’s t-test as all data had normal distribution. In the third step, we looked for correlations between BMD and clinical and biological parameters using Pearson’s correlation coeYcient.
BMD measurement BMD was determined by a Lunar Prodigy Vision DXA system (Lunar Corp., Madison, WI). The DXA scans were obtained by standard procedures supplied by the manufacturer for scanning and analysis. All BMD measurements were carried out by two experienced technicians. Daily quality control was carried out by measurement of a Lunar phantom. At the time of the study, phantom measurements showed stable results. The phantom precision expressed as the CV (%) was 0.08. Moreover, reproducibility has been assessed recently in clinical practice and showed a smallest
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Results Fifty-two patients attending the Neurology Department consented to take part in the study. The mean age was 60.0 years (range 30–77), 69.2% were men, and 96% were living independently. The sample had mean disease duration of 5 years since diagnosis of PD (range 0–17), with 18 (34.6%) having stage III and IV Hoehn and Yahr rating. The characteristics of the study population are outlined in Table 1. The results shown are for both the hip and spine.
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Table 1 Characteristics of the study population
Age (years)
Mean § SD Range
N (%)
60 § 9.2
[30–77]
– 36 (69.2)
Men
–
–
BMI (kg/m2)
25.5 § 5
[18.1–48] –
Onset age (years)
55.1 § 10.1 [20–71]
Disease duration (years)
4.9 § 4.5
[0.25–17] –
Hoehn and Yahr stage
2.0 § 1
[1–4]
–
Sunlight exposure
