Reduction in serum leptin and IGF-1 but preserved T-lymphocyte numbers andactivation after a ketogenic diet in rheumatoid arthritis patients

Objective To assess the clinical, immunological and hormonal effects of carbohydrate restriction in rheumatoid arthritis (RA) patients via the provision of a ke togenic diet. Methods Thirteen RA patients with active disease consumed a ketogenic diet for 7 da ys, providing the estimated requirements for energy and protein whilst rest ricting their carbohydrate intake to < 40 g/day. This was followed by a 2-w eek re-feeding period. Clinical and laboratory evaluations were carried out on days 0, 7 and 21. Changes in serum glucose, beta-hydroxybutyrate (beta- HB), leptin, insulin-like growth factor-1 (IGF-1) and cortisol were also me asured at these time points. To study CD4+ and CD8+ lymphocyte responses, m itogen stimulated T-cell activation was assessed in heparinised whole blood via flow-cytometric analysis of CD69 expression. Results After the 7-day ketogenic diet, there were significant increases in serum b eta-NB and cortisol, and significant decreases in body weight, the total ly mphocyte count, serum leptin, IGF-1 and glucose. However, with the exceptio n of morning stiffness, there were no significant changes in any of the cli nical or laboratory measures of disease activity or in early T-lymphocyte a ctivation and the absolute numbers of CD4+ and CD8+ cells. Conclusion In RA patients several of the metabolic and hormonal responses to a ketogen ic diet, such as a fall in serum IGF-1 and leptin, resemble those which occ ur in response to acute starvation. However, the clinical and immunological changes which occur in response to acute starvation do not take place with a ketogenic diet and thus may be dependent upon energy and/or protein rest riction.