To the Editor,
The study by Huang et al1 sheds valuable light on how obesity may cause depression. However, depressed people are known to be at higher risk for developing obesity in the first place.2 It is therefore important to know whether any of the participants had a history of prior depression. Other significant risk factors for depression such as concomitant physical illness, medication use, lack of family support and presence of pain should also be investigated. Depressive symptoms have been especially linked to general medical3 and, in particular, to cardiovascular conditions,4 which have a higher prevalence in obese individuals. In addition, the Beck Depression Inventory includes questions about physical symptoms such as fatigue, which may result in the scores being higher, since symptoms of illness may be confused with depression. Finally, insulin resistance was defined as a HOMA-IR (homeostasis model of assessment for insulin resistance) score of >1.64, whereas the most widely adopted HOMA-IR cutoff value is is 2.6.5
REFERENCES
1. Huang Y, Chen J, Yang J, et al, 2015 Evaluation of depressive symptoms in obese patients with or without acanthosis nigricans. Hormones (Athens) 14: 417-424.
2. Blaine B, 2008 Does depression cause obesity? A meta-analysis of longitudinal studies of depression and weight control. J Health Psychol 13: 1190-1197.
3. Katon WJ, 2003 Clinical and health services relationships between major depressive symptoms, and general medical illness. Biological Psychiatry 54: 216-226.
4. Musselman DL, Evans DL, Nemeroff CB, 1998 The relationship of depression to cardiovascular disease: Epidemiology, biology, and treatment. Arch Gen Psychiatry 55: 580-592.
5. Ascaso JF, Pardo S, Real JT, et al, 2003 Diagnosing Insulin Resistance by Simple Quantitative
Address for correspondence:
Bulent Canbaz, Ankara Numune Hospital, Department of Endocrinology, Ankara, Turkey; Tel.: +905325836353, Fax: +312 311 43 40, E-mail: dr.bulentcanbaz@gmail.com
Received: 29-11-2015, Accepted: 27-12-2015