Table 1.
Clinical studies showing an association between obesity and central nervous or peripheral neurological diseases.
| Study | Sample Size | Patients’ Features | Findings | Ref. |
|---|---|---|---|---|
| Central nervous system disorders | ||||
| Holtkamp et al., 2004 | 97 men | Children with attention-deficit/hyperactivity disorder (ADHD) | Obesity development independent of ADHD diagnosis | [69] |
| Elias et al., 2005 | 551 men, 872 women | Individuals with healthy body weight, overweight, obese | In men, obesity association with adverse cognitive effects | [59] |
| Cournot et al., 2006 | 1660 men, 1576 women | Healthy workers (32–62 years old) | Higher BMI association with lower cognitive scoresand higher cognitive decline | [60] |
| Boeka et al., 2008 | 20 men, 48 women | Caucasian and African American extremely obese patients | Evidence of specific cognitive dysfunction in extremely obese individuals | [73] |
| Sabia et al., 2009 | 3788 men, 1343 women | White individuals | Multiple effects of obesity on cognition | [61] |
| Hassing et al., 2010 | 140 men, 277 women | Swedish twin registry | Midlife overweight association to lower overall cognitive function in old age | [62] |
| Anstey et al., 2011 | 71529 individuals | Participants evaluated for any type of dementia | Overweight and obesity in midlife increase dementia risk | [64] |
| Dahl et al., 2013 | 280 men, 377 women | Swedish adoption and twin study of ageing | Midlife overweight or obesity responsible of lower cognitive function and cognitive decline in late life | [63] |
| Yau et al., 2014 | 30 obese, 30 lean adolescents | Obese without insulin resistance or metabolic syndrome | Uncomplicated obesity may result in subtle brain alterations | [72] |
| Cheke et al., 2016 | 14 men, 36 women | 8 Obese individuals, 16 overweight, 26 lean | Higher BMI association with lower performance on the what-where-when memory task | [66] |
| Navas et al., 2016 | 35 men, 44 women | 38 Normal weight, 21 overweight, 20 obese | Obesity is linked to a propensity to make risky decisions | [67] |
| Kummer et al., 2016 | 92 patients and 19 controls | Children and adolescents: autism spectrum disorder (ASD) andADHD | Higher risk of overweight and obesity in ASD and ADHD | [70] |
| Peripheral nervous system diseases | ||||
| Ylitalo et al., 2011 | 2514 adults aged ≥ 40 years | Individuals with peripheral neuropathy,peripheral vascular disease (PVD), alower-extremity diseases (LEDs). | Obesity and cardiometabolic clustering markedly increased the likelihood of LEDs | [92] |
| Tesfaye et al., 2005 | 1172 patients | Patients with type 1 diabetes mellitus. | Higher BMI independently associated with the incidence of neuropathy. | [93] |
| Ziegler et al., 2008 | 195 patients and 198 controls | Population-based MONICA/KORA Augsburg Surveys aged 25–74 years. | Waist circumference association with peripheral arterial disease (PAD) | [94] |
| Singleton et al., 2014 | 21 obese, 51 lean controls | Non-diabetic obese patients referred for Roux en Y bariatric surgery compared with lean controls. | Asymptomatic neuropathy is common in very obese patients independent of glucose control | [95] |