Summary of epidemiological studies on autism/autism spectrum disorder in the Gulf Cooperation countries.
| Author, Year, Ref | Country | Study design | Population | Sample size | Diagnostic criteria | Main findings |
|---|---|---|---|---|---|---|
| Prevalence studies | ||||||
| Eapen et al, 200718 | UAE | Cross sectional | Preschool children in UAE | 694 Emirati children (aged 3 years) | DSM-IV | Autism-screening questionnaire gave a prevalence of 58 per 10,000, after clinical evaluation the prevalence dropped to 29 per 10,000. Presence of autistic features was associated with males, behavioral problems, and family history of developmental delay |
| Al-Salehi et al, 200919 | Saudi Arabia | Cross sectional | Children in Saudi Arabia | 49 children diagnosed with ASD | DSM-IV CARS | Communication problems present in 71% of patients, consanguineous marriages 28.6%, male:female ratio 3:1, mean age at referral 6.3 years, behavioral problems present in 45% of patients. Most patients were self-referred or from primary care givers |
| Al-Farsi et al, 201120 | Oman | Cross sectional | All children in Oman aged 0-14 years | 800,000 | DSM-IV CARS | Prevalence 1.4 per 10,000 (95% CI: 1.2-1.7), prevalence was 2.5 times more in males, age-specific prevalence was highest among children aged 5-9 years |
| Al Ansary & Ahmed, 201317 | Bahrain | Case-control (case identification phase) | All children in Bahrain | Records from the only referral clinic in Bahrain from 2000-2010 (N = 100 cases) | DSM-IV-TR | Prevalence 4.3 per 10,000 population, with a male:female ratio of 4:1. |
| Risk factors/Biomarkers studies | ||||||
| Al-Gadani et al, 200924 | Saudi Arabia | Case-control | Children with autism in Saudi Arabia (age 3-15 years) | 30 cases, 30 (age and gender matched) healthy controls | DSM-IV | Lipid peroxidation, GSH-Px, and SOD were significantly higher in autistic patients while vitamin E and glutathione levels were lower. Vitamin C and catalase showed insignificant differences between groups. |
| Al-Mosalem et al, 200925 | Saudi Arabia | Case-control | Children with autism in Saudi Arabia (age 3-15 years) | 30 cases, 30 (age and gender matched) healthy controls | DSM-IV | Significant increases in activity of Na(+)/K(+)ATPase (148.8%) and lactate levels (40%) among autistic patients |
| Ali et al, 201127 | Oman | Case-control | Children with autism in Oman (age 3-5 years) | 40 ASD diagnosed cases, 40 controls (age and gender matched) | DSM-IV CARS | Serum homocysteine level among ASD patients was significantly higher than controls and reference range. Serum folate and Vitamin B12 levels were lower in autistic patients than controls |
| El-Ansary et al, 201126 | Saudi Arabia | Case-control | Children with autism in Saudi Arabia (age 4-12 years) | 26 ASD cases, and 26 age-matched controls | ADI-R ADOS 3DI | Fatty acid profile in autism patients was altered compared with controls. Most saturated fatty acids showed markedly increased levels while levels of polyunsaturated acids were lower in autistic patients. Area under the curve for the receiver-operating curve for specific fatty acids ranged from 0.611 to 1.0 |
| El-Ansary et al, 201122 | Saudi Arabia | Case-control | Children with autism in Saudi Arabia (age 4-12 years) | 25 autism cases, and 16 healthy controls (age-matched) | ADI-R ADOS 3DI | Autistic patients showed significantly higher blood lead level (Pb+2). Plasma levels of neurotransmitters (GABA, 5HT and DA) were elevated |
| Al-Ayadhi & Mostafa, 201123 | Saudi Arabia | Case-control | Children with autism in Saudi Arabia | 42 autistic children and 42 healthy controls | CARS | Significantly elevated serum osteopontin found in 81% of autistic patients. Severe autism showed higher osteopontin than mild or moderate autism. Osteopontin levels were positively correlated to CARS scores. |
| Al-Farsi et al, 201221 | Oman | Case-control | Children with ASD in Oman (aged 3-14 years) | 102 ASD diagnosed children, and 102 healthy controls | DSM-IV CARS | Increased risk of ASD was found in relation to: late initiation of breastfeeding (OR=1.47, 95% CI: 1.01-3.1) and no colostrum intake (OR=1.7, 95% CI: 1.03-4.3). Exclusive breastfeeding and continued breastfeeding up to 24 months significantly decreased risk of ASD |
| Al Ansary & Ahmed, 201317 and Al Ansary & Ahmed, 201216 | Bahrain | Case-control | Children with ASD in Bahrain | 350 Age and gender-matched controls nocturnal enuresis, mild behavior disorder and no psychopathology | DSM-IV-TR | Significant association with advanced maternal age above 30 years (OR = 1.83, CI: 1.02-3.28) and paternal age above 30 years (OR = 2.08, 95% CI: 1.15-3.7). Non-significant relation with birth order. Significant relationship with delivery by cesarean section and having mothers who suffered from prenatal complications |