Multiple sclerosis in Malta in 1999: an update

Incidence, prevalence and characteristics of MS in São Miguel, an island in the Atlantic

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory-demyelinating disease of the central nervous system (CNS). With approximately 2.3 million people estimated to live with MS globally, incidence and prevalence of the disease vary significantly across regions. Generically, the global distribution of MS varies with geographic latitude. However, MS epidemiological data in Southern Europe and Mediterranean countries revealed areas of unexpectedly high prevalence and incidence of MS, thereby demonstrating that clear exceptions to the variation of MS with latitude exist. Epidemiological evidence on MS in Portugal is limited to studies concerning specific regions of the country and therefore not representative of the entire country. More studies form different regions of the country are needed in order to effectively establish MS prevalence and incidence in Portugal. The aim of this study is to determine MS incidence and prevalence, as well as gather information on other clinical data in São Miguel, the biggest island of the Azores, a Portuguese archipelago situated in the North Atlantic.

METHODS

This is a cross-sectional study of MS patients from the only hospital of São Miguel, an island with a population of 137,150 habitants. Only patients from São Miguel were included in the study. 1/07/2019 was established as the prevalence day and demographic characteristics (sex, age at diagnosis and year of diagnosis) and clinical outcome (type of the disease, treatment, clinical severity score [EDSS]) were reported. 5-year Incidence of MS was studied from 1/07/2014 to 01/07/2019.

RESULTS

47 patients were enrolled in the study, 27 (57.4%) were female and 20 (42.6%) were male. 43 patients were classified as having RRMS and 4 patients classified as having SPMS. Prevalence of MS in São Miguel island was 34.3/100.000. The prevalence for females was 38.5/100.000 and for males was 29.9/100.000. Age-adjusted and sex-adjusted (to the population of the European Union in 2019) MS prevalence were 31.1/100.000 and 34.3/100.000 respectively. Incidence was 2.04/100,000 person-years for the overall population, 2.56/100,000 person-years for females and 1.49/100,000 person-years for males. Age-adjusted and sex-adjusted MS incidence were 1.74/100.000 person-years and 2.04/100.000 person-years respectively. Regarding clinical characteristics, the mean EDSS was 2.93 ± 1.85, the mean age at the time of the diagnosis was 31.77 ± 8.47 years and the mean time of evolution of the disease (period between diagnosis and prevalence date) was 9.19 ± 6.55 years. Treatment options were diverse and included first and second-line treatments as well as Immune reconstitution therapies. Interferon-beta was the most prescribed medication. 2 patients were not making any DMT.

CONCLUSIONS

The incidence and prevalence of MS reported by our study is lower than what was registered by other studies. Several reasons may explain these results such as the ancestry of the population of São Miguel, migratory flows and limitations in detecting all MS patients. Incidence and prevalence were higher in females. A marked heterogeneity in clinical characteristics was seen, with great variability in degree of disability, age at diagnosis and time of MS evolution. Treatment options were quite varied in the population, with Interferon-beta being the most prescribed DMT.

Changing epidemiology of immune-mediated inflammatory diseases in immigrants: A systematic review of population-based studies

BACKGROUND

Immune-mediated inflammatory diseases (IMIDs) are systemic diseases of multifactorial etiology that share aberrant immune responses as the common final pathway. With rising globalization, their incidence is increasing in developing countries and among immigrants. Our primary objective was to systematically review the epidemiology of IMIDs in immigrants and conduct a meta-analysis to estimate the risk of IMIDs in immigrant populations according to their origin and destination countries.

METHODS

We systematically searched five biomedical databases and reviewed population-based studies, from inception through August 2018, that reported incidence or prevalence data of inflammatory bowel disease (IBD), multiple sclerosis (MS), type 1 diabetes (T1D), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ankylosing spondylitis (AS) or psoriasis and psoriatic arthritis (PPA) among immigrants and the host population.

RESULTS

The incidence and prevalence of IMIDs among immigrants differ from host populations, and evolve over subsequent generations. The risk of IBD among immigrants approximates that in hosts, especially among South Asians, with ulcerative colitis incidence changing prior to Crohn's disease incidence. MS risk is highest in Iranian immigrants, T1D in African immigrants and SLE in African and Iraqi immigrants. Data on other IMIDs are sparse. Significant heterogeneity between the studies precluded meta-analysis.

CONCLUSION

Based on our systematic review, the epidemiology of IMIDs among immigrants varies according to native and host countries, immigrant generation, and IMID type. The rapid evolution suggests a role for non-genetic factors and gene-environment interactions. Future studies should focus on these pattern shifts, given implications of rising global burden of IMIDs and immigration.

The Interaction between Viral and Environmental Risk Factors in the Pathogenesis of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic debilitating inflammatory disease of unknown ethology targeting the central nervous system (CNS). MS has a polysymptomatic onset and is usually first diagnosed between the ages of 20–40 years. The pathology of the disease is characterized by immune mediated demyelination in the CNS. Although there is no clinical finding unique to MS, characteristic symptoms include sensory symptoms visual and motor impairment. No definitive trigger for the development of MS has been identified but large-scale population studies have described several epidemiological risk factors for the disease. This list is a confusing one including latitude, vitamin D (vitD) levels, genetics, infection with Epstein Barr Virus (EBV) and endogenous retrovirus (ERV) reactivation. This review will look at the evidence for each of these and the potential links between these disparate risk factors and the known molecular disease pathogenesis to describe potential hypotheses for the triggering of MS pathology.

A Systematic Assessment of Prevalence, Incidence and Regional Distribution of Multiple Sclerosis in Bavaria From 2006 to 2015

Introduction: Worldwide, incidence and prevalence of multiple sclerosis (MS) have increased over the last decades. We present a systematic epidemiological study with recent prevalence and incidence rates of MS in Bavaria. Methods: Incidence and prevalence of MS stratified by gender, age groups and region were analyzed by data records from 2006 to 2015 of more than 10 million people insured by the Bavarian Association of Statutory Health Insurance Physicians. Official statistics of the German Federal Ministry of Health provided the size of the general population. Future prevalence was estimated with a predictive model. Results: From 2006 to 2015 prevalence of MS in Bavaria increased from 171 per 100,000 to 277 per 100,000, while incidence rates remained relatively stable (range 16-18 per 100,000 inhabitants with a female to male ratio between 2.4:1 and 2:1). Incidence and prevalence were higher in urban than urbanized and rural areas. The prevalence is expected to increase to 374 per 100,000 in 2040 with the highest prevalence rates between 50 and 65 years. Conclusion: The prevalence of MS in Bavaria is among the highest worldwide and will further rise over the next two decades. This demonstrates a need to strengthen healthcare provision systems due to the increasing numbers of particularly older patients with MS in the future.

Incidence and prevalence of multiple sclerosis in Europe: a systematic review

BACKGROUND

Multiple sclerosis (MS) is the most common cause of neurological disability in young adults worldwide and approximately half of those affected are in Europe. The assessment of differential incidence and prevalence across populations can reveal spatial, temporal and demographic patterns which are important for identifying genetic and environmental factors contributing to MS. However, study methodologies vary and the quality of the methods can influence the estimates. This study aimed to systematically review European studies of incidence and prevalence of MS and to provide a quantitative assessment of their methodological quality.

METHODS

A comprehensive literature search was performed to obtain all original population-based studies of MS incidence and prevalence in European populations conducted and published between January 1985 and January 2011. Only peer-reviewed full-text articles published in English or French were included. All abstracts were screened for eligibility and two trained reviewers abstracted the data and graded the quality of each study using a tool specifically designed for this study.

RESULTS

There were 123 studies that met the inclusion criteria. The study estimates were highly heterogeneous, even within regions or countries. Quality was generally higher in the more recent studies, which also tended to use current diagnostic criteria. Prevalence and incidence estimates tended to be higher in the more recent studies and were higher in the Nordic countries and in northern regions of the British Isles. With rare exceptions, prevalence and incidence estimates were higher in women with ratios as high as 3:1. Few studies examined ethnicity. Epidemiological data at the national level was uncommon and there were marked geographical disparities in available data, with large areas of Europe unrepresented and other regions well-represented in the literature. Only 37% of the studies provided standardized estimates.

CONCLUSIONS

Despite the breadth of the literature on the epidemiology of MS in Europe, inter-study comparisons are hampered by the lack of standardization. Further research should focus on regions not yet studied and the evaluation of ethnic differences in MS prevalence and incidence. National-level studies using current diagnostic criteria, validated case definitions and similar age- and sex-standardization would allow better geographical comparisons.

Geomagnetic disturbances may be environmental risk factor for multiple sclerosis: an ecological study of 111 locations in 24 countries

BACKGROUND

We noticed that a hypothesis based on the effect of geomagnetic disturbances (GMD) has the ability to explain special features of multiple sclerosis (MS). Areas around geomagnetic 60 degree latitude (GM60L) experience the greatest amount of GMD. The easiest way to evaluate our hypothesis was to test the association of MS prevalence (MSP) with angular distance to geomagnetic 60 degree latitude (AMAG60) and compare it with the known association of MS with geographical latitude (GL). We did the same with angular distance to geographic 60 degree latitude (AGRAPH60) as a control.

METHODS

English written papers with MSP keywords, done in Europe (EUR), North America (NA) or Australasia (AUS) were retrieved from the PubMed. Geomagnetic coordinates were determined for each location and AMAG60 was calculated as absolute value of numerical difference between its geomagnetic latitude from GM60L. By an ecological study with using meta-regression analyses, the relationship of MSP with GL, AMAG60 and AGRAPH60 were evaluated separately. MSP data were weighted by square root of number of prevalent cases. Models were compared by their adjusted R square (AR2) and standard error of estimate (SEE).

RESULTS

111 MSP data were entered in the study. In each continent, AMAG60 had the best correlation with MSP, the largest AR2 (0.47, 0.42 and 0.84 for EUR, NA and AUS, respectively) and the least SEE. Merging both hemispheres data, AMAG60 explained 56% of MSP variations with the least SEE (R = 0.75, AR2 = 0.56, SEE = 57), while GL explained 17% (R = 0.41, AR2 = 0.17, SEE = 78.5) and AGRAPH60 explained 12% of that variations with the highest SEE (R = 0.35, AR2 = 0.12, SEE = 80.5).

CONCLUSIONS

Our results confirmed that AMAG60 is the best describer of MSP variations and has the strongest association with MSP distribution. They clarified that the well-known latitudinal gradient of MSP may be actually a gradient related to GM60L. Moreover, the location of GM60L can elucidate why MSP has parabolic and linear gradient in the north and south hemisphere, respectively. This preliminary evaluation supported that GMD can be the mysterious environmental risk factor for MS. We believe that this hypothesis deserves to be considered for further validation studies.

Cost of disorders of the brain in Europe 2010

BACKGROUND

The spectrum of disorders of the brain is large, covering hundreds of disorders that are listed in either the mental or neurological disorder chapters of the established international diagnostic classification systems. These disorders have a high prevalence as well as short- and long-term impairments and disabilities. Therefore they are an emotional, financial and social burden to the patients, their families and their social network. In a 2005 landmark study, we estimated for the first time the annual cost of 12 major groups of disorders of the brain in Europe and gave a conservative estimate of €386 billion for the year 2004. This estimate was limited in scope and conservative due to the lack of sufficiently comprehensive epidemiological and/or economic data on several important diagnostic groups. We are now in a position to substantially improve and revise the 2004 estimates. In the present report we cover 19 major groups of disorders, 7 more than previously, of an increased range of age groups and more cost items. We therefore present much improved cost estimates. Our revised estimates also now include the new EU member states, and hence a population of 514 million people.

AIMS

To estimate the number of persons with defined disorders of the brain in Europe in 2010, the total cost per person related to each disease in terms of direct and indirect costs, and an estimate of the total cost per disorder and country.

METHODS

The best available estimates of the prevalence and cost per person for 19 groups of disorders of the brain (covering well over 100 specific disorders) were identified via a systematic review of the published literature. Together with the twelve disorders included in 2004, the following range of mental and neurologic groups of disorders is covered: addictive disorders, affective disorders, anxiety disorders, brain tumor, childhood and adolescent disorders (developmental disorders), dementia, eating disorders, epilepsy, mental retardation, migraine, multiple sclerosis, neuromuscular disorders, Parkinson's disease, personality disorders, psychotic disorders, sleep disorders, somatoform disorders, stroke, and traumatic brain injury. Epidemiologic panels were charged to complete the literature review for each disorder in order to estimate the 12-month prevalence, and health economic panels were charged to estimate best cost-estimates. A cost model was developed to combine the epidemiologic and economic data and estimate the total cost of each disorder in each of 30 European countries (EU27+Iceland, Norway and Switzerland). The cost model was populated with national statistics from Eurostat to adjust all costs to 2010 values, converting all local currencies to Euro, imputing costs for countries where no data were available, and aggregating country estimates to purchasing power parity adjusted estimates for the total cost of disorders of the brain in Europe 2010.

RESULTS

The total cost of disorders of the brain was estimated at €798 billion in 2010. Direct costs constitute the majority of costs (37% direct healthcare costs and 23% direct non-medical costs) whereas the remaining 40% were indirect costs associated with patients' production losses. On average, the estimated cost per person with a disorder of the brain in Europe ranged between €285 for headache and €30,000 for neuromuscular disorders. The European per capita cost of disorders of the brain was €1550 on average but varied by country. The cost (in billion €PPP 2010) of the disorders of the brain included in this study was as follows: addiction: €65.7; anxiety disorders: €74.4; brain tumor: €5.2; child/adolescent disorders: €21.3; dementia: €105.2; eating disorders: €0.8; epilepsy: €13.8; headache: €43.5; mental retardation: €43.3; mood disorders: €113.4; multiple sclerosis: €14.6; neuromuscular disorders: €7.7; Parkinson's disease: €13.9; personality disorders: €27.3; psychotic disorders: €93.9; sleep disorders: €35.4; somatoform disorder: €21.2; stroke: €64.1; traumatic brain injury: €33.0. It should be noted that the revised estimate of those disorders included in the previous 2004 report constituted €477 billion, by and large confirming our previous study results after considering the inflation and population increase since 2004. Further, our results were consistent with administrative data on the health care expenditure in Europe, and comparable to previous studies on the cost of specific disorders in Europe. Our estimates were lower than comparable estimates from the US.

DISCUSSION

This study was based on the best currently available data in Europe and our model enabled extrapolation to countries where no data could be found. Still, the scarcity of data is an important source of uncertainty in our estimates and may imply over- or underestimations in some disorders and countries. Even though this review included many disorders, diagnoses, age groups and cost items that were omitted in 2004, there are still remaining disorders that could not be included due to limitations in the available data. We therefore consider our estimate of the total cost of the disorders of the brain in Europe to be conservative. In terms of the health economic burden outlined in this report, disorders of the brain likely constitute the number one economic challenge for European health care, now and in the future. Data presented in this report should be considered by all stakeholder groups, including policy makers, industry and patient advocacy groups, to reconsider the current science, research and public health agenda and define a coordinated plan of action of various levels to address the associated challenges.

RECOMMENDATIONS

Political action is required in light of the present high cost of disorders of the brain. Funding of brain research must be increased; care for patients with brain disorders as well as teaching at medical schools and other health related educations must be quantitatively and qualitatively improved, including psychological treatments. The current move of the pharmaceutical industry away from brain related indications must be halted and reversed. Continued research into the cost of the many disorders not included in the present study is warranted. It is essential that not only the EU but also the national governments forcefully support these initiatives.

Epidemiology of multiple sclerosis in south-western Sardinia

BACKGROUND

Sardinia is a known high-risk area for multiple sclerosis (MS), but no data for south-western Sardinia (SWS) are available. SWS has a genetically homogeneous population, apart from St Peter Island, and represents a peculiar environment related to the industrial, mineralogical and military economy.

OBJECTIVE

To estimate prevalence and incidence and to evaluate temporal trends and geographical distribution of MS in SWS.

METHODS

MS prevalence was evaluated on 31 December 2007 and crude mean annual incidence rate was defined between 2003 and 2007. Temporal trend in MS incidence was assessed using the Armitage test. To identify MS clusters, Standard Morbidity Ratio (SMR) was calculated for each village and geographical distribution prevalence by means of a Bayesian hierarchical model.

RESULTS

Total crude prevalence rate was 210.4 (95% CI 186.3-234.5): 280.3 (95% CI 241.4-319.3) for females, 138 (95% CI 110.1-165.8) for males. The crude mean annual incidence rate was 9.7/100,000 (95% CI 3.4-13.2): 4.7/100,000 (95% CI 2.4-17.0) and 14.6/100,000 (95% CI 11.8-34.8) for males and females respectively. MS incidence has increased over the last 50 years. Cluster analysis showed an SMR of 0.2 (95% CI 0.05-0.68, p = 0.002) on the island of San Pietro, and 2.0 (95% CI 1.35-2.95, p = 0.001) in Domusnovas. Spatial distribution of MS was confirmed by Bayesian geographical analysis.

CONCLUSIONS

Our data confirm Sardinia as a high-risk area for MS and support the relevance of genetic factors in MS, as evidenced in St Peter Island. However, we found an unexpectedly high MS prevalence in one village, in particular in males, suggesting an environmental influence on MS occurrence.

Increasing frequency of multiple sclerosis in Catania, Sicily: a 30-year survey

Background and Objective: The objective of this study was to determine the prevalence and incidence of multiple sclerosis (MS) and its temporal profiles from 1975 to 2005 in the city of Catania.

Methods: The incidence of MS from 1975 to 31 December 1999 had been previously investigated by the same group. The frequency of MS in the community of Catania from 1 January 2000 to 31 December 2004 was studied in a population of 313,110 inhabitants (2001 census). All patients who satisfied Poser’s criteria were considered as prevalent and incident cases.

Results: Three hundred and ninety-eight patients with MS who had experienced the clinical onset of the disease before 31 December 2004 were found in a population of 313,110 inhabitants. The prevalence rate was 127.1/100,000 [95% confidence interval (CI) 115.1–140.4]. From 2000 to 2004, 108 patients with MS had clinical onset of the disease . The mean annual incidence was 7.0/100,000 (95% CI 5.7–13.7) and was higher in women (8.4/100,000; 95% CI 6.4–10.5) than in men (5.3/100,000; 95% CI 3.7–7.2). The mean length of time between the date of clinical onset and the date of the diagnosis was 1.4 ± 1.7 years. During the last 30 years the incidence of MS in this population increased from 1.3/100,000 during the first quinquennium (1975–9) to 7.0/100,000 during 2000–4.

Conclusions: Incidence rates have further increased in this population, suggesting that the risk of MS is still increasing.

Epidemiology of multiple sclerosis in Europe: a review

Multiple sclerosis (MS) is a progressive demyelinating and degenerative disease of the CNS with symptoms dependent on the type of the disease and the site of lesions. During the progression of the disease, symptoms become more permanent and progressive disability ensues. MS is a disease characterized by wide variations between patients, thus making categorization difficult. The aim of the current study was to review the existing epidemiological data of MS in Europe published during the last decade (2000-2009), using PubMed. Findings revealed an increasing incidence of MS during the last decade. Recent data indicate that latitude does not play a key role in determining the onset of the disease. MS has a significant impact on the quality of life for most patients over many years. The disease is twice as common in women than in men, and is at its peak in the most economically productive years of life. Pregnancy, postpartum status and vaccines may influence the onset and the course of the disease. Only one of the reviewed papers provides a view of progression from onset to death.

The changing demographic pattern of multiple sclerosis epidemiology

The uneven distribution of multiple sclerosis (MS) across populations can be attributed to differences in genes and the environment and their interaction. Prevalence and incidence surveys could be affected by inaccuracy of diagnosis and ascertainment, and prevalence also depends on survival. These sources of error might play a part in the geographical and temporal variations. Our literature search and meta-regression analyses indicated an almost universal increase in prevalence and incidence of MS over time; they challenge the well accepted theory of a latitudinal gradient of incidence of MS in Europe and North America, while this gradient is still apparent for Australia and New Zealand; and suggest a general, although not ubiquitous, increase in incidence of MS in females. The latter observation should prompt epidemiological studies to focus on changes in lifestyle in females. New insights into gene-environment and gene-gene interactions complicate interpretations of demographic epidemiology and have made obsolete the idea of simple causative associations between genes or the environment and MS.

Epidemiology of Multiple Sclerosis

This chapter discusses the environmental factors associated to epidemiology of multiple sclerosis. The epidemiologic evidence points to three environ­mental risk factors—infection with the Epstein-Barr virus (EBV), low levels of vitamin D, and cigarette smoking—whose association with multiple sclerosis (MS) seems to satisfy in varying degrees most of the criteria that support causality, including temporality, strength, consis­tency, biologic gradient, and plausibility. None of these associations, however, has been tested experimentally in humans and only one––vitamin D deficiency is presently amenable to experimental interventions. The evidence, albeit more sparse and inconsistent, linking other environmental factors to MS risk are summarized. Epidemiologic clues to the hypothetical role of infection in MS are com­plex and often seem to point in opposite directions. The ecological studies, database/linkage analyses, and longitudinal studies of sunlight exposure and vitamin D are reviewed. Biologic mechanisms for smoking and increased risk of MS could be neuro­toxic, immunomodulatory, vascular, or they could involve increased frequency and duration of respiratory infections. Some other possible risk factors include––diet and hepatitis B vaccine.

Type 1 diabetes mellitus and multiple sclerosis: common etiological features

Type 1 diabetes mellitus and multiple sclerosis have been largely seen as different, organ-specific diseases, which are managed by different medical specialties. Research studies on these diseases have for the most part followed independent tracks. In this Review, we highlight the latest epidemiological and genetic findings, which have identified many features common to both disorders. Experts consider it increasingly likely that the environment contributes substantially to this overlap. However, although genetic elements that are distinct to each disease probably determine the ultimate form of autoimmunity that is manifested, strikingly broad parallels are seen between the components of genetic risk of type 1 diabetes mellitus and multiple sclerosis. Similarities and differences between these two diseases draw attention to shared disease pathways but insights into each disorder are providing mutual illumination of their pathogenesis.

Comparative features of the epidemiology of multiple sclerosis and Parkinson's disease: Environmental factors of potential etiological importance

Multiple sclerosis (MS) and Parkinson's disease (PD) are diseases of unknown cause. The etiology of MS is usually considered to be due to a number of potential biological agents while the etiology of PD is usually associated with toxic agents. Despite these differences, both pathologies have strong epidemiological similarities. A comparative analysis is performed of the epidemiology of MS and PD. Potential causal factors for PD may include dopamine-like pharmacological agents. It is proposed that potential causal agents such as certain drugs plus certain vaccines could explain rationally the epidemiology of MS. Ecology and genetics could not be the appropriate lines of research in the etiology of MS/PD because they are supported only in part by the epidemiology.

The epidemiology of multiple sclerosis in Europe

Multiple sclerosis (MS) is a chronic and potentially highly disabling disorder with considerable social impact and economic consequences. It is the major cause of non-traumatic disability in young adults. The social costs associated with MS are high because of its long duration, the early loss of productivity, the need for assistance in activities of daily living and the use of immunomodulatory treatments and multidisciplinary health care. Available MS epidemiological estimates are aimed at providing a measure of the disease burden in Europe. The total estimated prevalence rate of MS for the past three decades is 83 per 100,000 with higher rates in northern countries and a female:male ratio around 2.0. Prevalence rates are higher for women for all countries considered. The highest prevalence rates have been estimated for the age group 35-64 years for both sexes and for all countries. The estimated European mean annual MS incidence rate is 4.3 cases per 100,000. The mean distribution by disease course and by disability is also reported. Despite the wealth of epidemiological data on MS, comparing epidemiological indices among European countries is a hard task and often leads only to approximate estimates. This represents a major methodological concern when evaluating the MS burden in Europe and when implementing specific cost-of-illness studies.

The prevalence of multiple sclerosis in the District of Santarém, Portugal

The prevalence of multiple sclerosis (MS) in Portugal is still unknown. Recent studies conducted in southern European countries showed higher than expected rates of MS prevalence. In an attempt to evaluate the MS prevalence in Santarém--a district with 62621 inhabitants (1991 census) located in the centre of Portugal--we have conducted a population survey in this district for five years. The crude prevalence rate found was 46.3/100,000. This figure is not different from findings recently reported in studies conducted at similar latitudes in neighbour southern European countries. This was the first population survey conducted in Portugal, and it is the first accurate contribution to the knowledge of the MS prevalence in this country.

Biochemical Indices of Renal Osteodystrophy in Dialysis Patients on the Island of Malta

OBJECTIVES

Renal osteodystrophy (ROD) has never been studied on the small Mediterranean island of Malta, which has a largely inbred population. The genetic contribution to the pattern of renal osteodystrophy is being increasingly recognized. We were, thus, interested in studying indices of bone turnover in Maltese end stage renal failure patients.

MATERIALS AND METHODS

Sixty unselected patients, representing 65% of all patients undergoing dialysis in the island's renal unit, were prospectively investigated over a period of 5 months with respect to symptoms, calcium/phosphate chemistry, intact parathyroid hormone (iPTH) and bone alkaline phosphatase (bAP). Bone histomorphometry, which is the gold standard in the diagnosis of ROD, was not within the reach of our small unit. Biochemical markers may not be as sensitive and specific as bone biopsy for individual patient diagnosis of ROD sub-type but they can give a fairly good indication of the spectrum of bone turnover on a population basis. The optimum combination of biochemical marker cut-offs available from studies in the literature was then employed to estimate bone turnover.

RESULTS

The following biochemical picture emerged: 42% had iPTH < 79.7 pg/ml (which cut off has a reported specificity of 93.7% for low turnover bone disease), 45% had iPTH > 100 pg/ml and bAP > 10 ng/ml (which combined cut off has a reported specificity of 100% for high turnover bone disease), while 13% could not be classified (ie had intermediate values).

CONCLUSIONS

Based on biochemical data, the pattern of bone turnover seems to be comparable to the European average. Further indepth study using bone histomorphometry is warranted.

Prevalence and incidence of multiple sclerosis in Las Palmas, Canary Islands, Spain

OBJECTIVES

To determine the prevalence and incidence of multiple sclerosis (MS) in the city of Las Palmas (Canary Islands, Spain), geographically belonging to north-western Africa, but with European ancestry.

METHODS

This population-based survey was conducted for a period of 5 years (1998-2002) in a Sanitary District of Las Palmas city (28 degrees 20' N), with a population of 82,623 inhabitants. Multiple sources were periodically investigated for case ascertainment. Patients with definite and probable MS were included.

RESULTS

Sixty-four patients with MS were identified on prevalence day, December 31, 2002. According to Poser's criteria the crude prevalence rate was 77.5 per 100,000 (95% CI: 59.7-98.9). This rate decreased to 73.8 (95% CI: 56.5-94.8) according to McDonald's criteria. Age-adjusted rates for the world and European standard populations were 61.6 (95% CI: 47.1-78.9) and 70.6 (95% CI: 55-89), respectively. Prevalence was higher for women aged 25-44 years. In 17 patients onset of MS occurred within the study period. Average annual incidence was 4.1 per 100,000 (95% CI: 2.4-6.6).

CONCLUSIONS

The prevalence and incidence rates in Las Palmas city are close to those reported from Continental Spain and other countries of southern Europe with similar social and ethnic background. These results highlight the role of racial-ethnic factors in the genesis of MS.

Multiple Sclerosis in Southern Europe: Monreale City, Italy

BACKGROUND

Several follow-up studies showed increasing prevalence and incidence rates for multiple sclerosis (MS).

OBJECTIVE

To ascertain, throughout a follow-up study, the incidence and prevalence of MS in the city of Monreale, Sicily, southern Italy.

METHODS

We calculated crude and age- and sex-specific prevalence rates on December 31, 2000, and determined incidence rates for the period January 1, 1992 to December 31, 2000.

RESULTS

The prevalence of MS was 71.2 per 100,000 population (48,5/100,000 in men; 93,0/100,000 in women). The incidence rate of MS for the period 1992-2000 was 4.0/100,000 per year.

CONCLUSION

This study showed a nonsignificant increase in MS incidence rates in Monreale city for 1992-2000 compared to 1981-1991. Prevalence rates were similar to those of the previous follow-up study. Intervals between onset of symptoms and diagnosis seemed shorter than in prior studies. There is no evidence that the high prevalence and incidence rates have changed in this interval but numbers are too small for firm statements. These findings indicate that in Monreale city MS prevalence is stable and confirm Sicily as a high-risk area for MS.