Andrea Fontana1, Benoit Marin2, Jaime Luna3,4, Ettore Beghi5, Giancarlo Logroscino6,7, Farid Boumédiene3, Pierre-Marie Preux3,8, Philippe Couratier3,4, Massimilano Copetti1. 1. Unit of Biostatistics, Fondazione IRCCS Casa Sollievo Della Sofferenza, San Giovanni Rotondo, Italy. 2. Ministère de la Sante et des Solidarités, Cellule Interministérielle Recherche MSS/MESRI, Paris, France. benoit.marin@sante.gouv.fr. 3. INSERM, Univ. Limoges, CHU Limoges, IRD, U1094 Tropical Neuroepidemiology, Institute of Epidemiology and Tropical Neurology, GEIST, Limoges, France. 4. CHU Limoges, Department of Neurology, ALS Expert Center, Limoges, France. 5. Laboratorio di Malattie Neurologiche, Istituto di Ricerche Farmacologiche Mario Negri, Milano IRCCS, Milan, Italy. 6. Unit of Neurodegenerative Diseases, Department of Clinical Research in Neurology, University of Bari "Aldo Moro", at "Pia Fondazione Cardinale G. Panico", 73039, Tricase, Lecce, Italy. 7. Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, Italy. 8. CHU Limoges, Centre d'Epidémiologie, de Biostatistique et de Méthodologie de la Recherche, Limoges, France.
Abstract
BACKGROUND: A noticeable change of the male-to-female sex ratio (SR) has been observed in Amyotrophic Lateral Sclerosis (ALS) leading to an apparent regression of SR with time (SR close to 1:1). OBJECTIVE: To provide a global SR estimate and investigate its relation with respect to population age. METHODS: A systematic review and meta-analysis was conducted including only population-based studies with a high-quality methodology in European ancestral origin population. Male-to-female SR was estimated by three different measures: SR number, SR crude incidence and SR standardized incidence. Standard and dose-response meta-analyses were performed to assess the pooled SR measures (irrespective of population age) and the evolution of the SR measures with respect to population age, respectively. Potential sources of heterogeneity were investigated via meta-regression. RESULTS: Overall, 3254 articles were retrieved in the literature search. Thirty-nine studies stratified by time periods were included. The overall pooled male-to-female ratio was 1.28 (95% CI 1.23-1.32) for SR number, 1.33 (95% CI 1.29-1.38) for SR crude incidence and 1.35 (95% CI 1.31-1.40) for SR standardized incidence. The SR number with respect to population age reveals a progressive reduction of SR at increasing age, while the SR crude incidence in relation to age displays a U-shaped curve. CONCLUSIONS: The number and the incidence of ALS cases were consistently higher in males than females. Dose-response meta-analysis showed that SR measures change with respect to population age. Further original research is needed to clarify if our findings are reproducible in other populations.
BACKGROUND: A noticeable change of the male-to-female sex ratio (SR) has been observed in Amyotrophic Lateral Sclerosis (ALS) leading to an apparent regression of SR with time (SR close to 1:1). OBJECTIVE: To provide a global SR estimate and investigate its relation with respect to population age. METHODS: A systematic review and meta-analysis was conducted including only population-based studies with a high-quality methodology in European ancestral origin population. Male-to-female SR was estimated by three different measures: SR number, SR crude incidence and SR standardized incidence. Standard and dose-response meta-analyses were performed to assess the pooled SR measures (irrespective of population age) and the evolution of the SR measures with respect to population age, respectively. Potential sources of heterogeneity were investigated via meta-regression. RESULTS: Overall, 3254 articles were retrieved in the literature search. Thirty-nine studies stratified by time periods were included. The overall pooled male-to-female ratio was 1.28 (95% CI 1.23-1.32) for SR number, 1.33 (95% CI 1.29-1.38) for SR crude incidence and 1.35 (95% CI 1.31-1.40) for SR standardized incidence. The SR number with respect to population age reveals a progressive reduction of SR at increasing age, while the SR crude incidence in relation to age displays a U-shaped curve. CONCLUSIONS: The number and the incidence of ALS cases were consistently higher in males than females. Dose-response meta-analysis showed that SR measures change with respect to population age. Further original research is needed to clarify if our findings are reproducible in other populations.
Authors: D F Stroup; J A Berlin; S C Morton; I Olkin; G D Williamson; D Rennie; D Moher; B J Becker; T A Sipe; S B Thacker Journal: JAMA Date: 2000-04-19 Impact factor: 56.272
Authors: G Logroscino; B J Traynor; O Hardiman; A Chio'; P Couratier; J D Mitchell; R J Swingler; E Beghi Journal: J Neurol Neurosurg Psychiatry Date: 2008-01 Impact factor: 10.154
Authors: Phan H Truong; Peter J Crouch; James B W Hilton; Catriona A McLean; Roberto Cappai; Giuseppe D Ciccotosto Journal: Cell Mol Life Sci Date: 2021-09-02 Impact factor: 9.261