Schizophrenia Bulletin Advance Access originally published online on January 18, 2008
Schizophrenia Bulletin 2009 35(1):213-221; doi:10.1093/schbul/sbm153
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© 2008 The Authors
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Impaired Flush Response to Niacin Skin Patch Among Schizophrenia Patients and Their Nonpsychotic Relatives: The Effect of Genetic Loading
2 Ju Shan Hospital, Taoyuan, Taiwan
3 Department of Psychiatry, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan
4 Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei, Taiwan
5 Department of Psychiatry, Far Eastern Memorial Hospital, Taipei, Taiwan
1 To whom correspondence should be addressed; 17 Xuzhou Road, Taipei 100, Taiwan; tel: 886-2-33228010, fax: 886-2-33228004, e-mail: wjchen{at}ntu.edu.tw.
We previously reported familial aggregation in flush response to niacin skin patch among schizophrenia patients and their nonpsychotic relatives. However, little is known about whether this abnormal skin response is associated with genetic loading for schizophrenia. This study compared the niacin flush response in subjects from families with only one member affected with schizophrenia (simplex families) with those from families having a sib-pair with schizophrenia (multiplex families). Subjects were patients with schizophrenia and their nonpsychotic first-degree relatives from simplex families (176 probands, 260 parents, and 80 siblings) and multiplex families (311 probands, 180 parents, and 52 siblings) as well as 94 healthy controls. Niacin patches of 3 concentrations (0.001M, 0.01M, and 0.1M) were applied to forearm skin, and the flush response was rated at 5, 10, and 15 minutes, respectively, with a 4-point scale. More attenuated flush response to topical niacin was shown in schizophrenia probands and their relatives from multiplex families than in their counterparts from simplex families, and the differentiation was better revealed using 0.1M concentration of niacin than 0.01M or 0.001M. For the highest concentration of 0.1M and the longest time lag of 15 minutes, a subgroup of probands (23%), parents (27%), and siblings (19%) still exhibited nonflush response. Flush response to niacin skin patch is more impaired in schizophrenia patients and their relatives from families with higher genetic loading for schizophrenia, and this finding has implications for future genetic dissection of schizophrenia.
Keywords: nicotinic acid / niacin skin test / prostaglandin / vulnerability indicator