¹Japan Women's University, The Division of Clinical Nutrition, Tokyo, Japan

²Japanese Red Cross Medical Center, Internal Medicine, Tokyo, Japan

Correspondence to: N Mito, The Division of Clinical Nutrition, Japan Women's University, 2-8-1, Mejirodai, Bunkyo-ku, Tokyo 112-8681, Japan. E-mail: g9951004@jwu.ac.jp

Guarantor: K Sato.

Contributors: NM developed the original idea, contributed to study design, data collection and analysis, and the writing of the paper. TH was responsible for selection of patients, contributed to data collection and editing of the paper. TH and CK contributed to data analysis and study coordination. KS developed the original idea, contributed to study design, study coordination and the writing of the paper.

Objective: To understand the effect of obesity and insulin on immune functions in non-insulin-dependent diabetes mellitus (NIDDM).

Subject: Fourteen obese NIDDM (body mass index (BMI)=30.6±1.1), seven non-obese NIDDM (BMI=24.2±0.5) and five obese non-NIDDM (BMI=28.3±0.67).

Interventions: We first examined the influence of insulin on the proliferation of several human cell lines. Second, we compared several immune functions between obese and non-obese NIDDM, and obese non-NIDDM patients using peripheral blood mononuclear cells.

Result: Insulin decreased proliferation of T-cell lines but not that of other types of cell lines. Furthermore, obesity augmented the production of IL-1 which could have cytotoxity against islet cells in NIDDM.

Conclusion: Our data suggested that the pathophysiology of NIDDM could be affected by the change of immunity due to obesity, and the treatment of obesity in NIDDM may be important from an immunological aspect.

European Journal of Clinical Nutrition (2002) 56, 347-351. DOI: 10/1038/sj/ejcn/1601324

obesity; immunity; insulin