Assessment of Nutritional Status in Rheumatic Diseases and Association to Disease Activity

Rheumatoid arthritis (RA) is an autoimmune, progressive, systemic disease of connective tissue. It is characterized by arthritis (symmetrical in most cases), extra-articular and systemic change. Spondyloarthritis (SpA) is an interconnected group of rheumatic disorders including ankylosing spondylitis (AS) and psoriatic arthritis (PsA), characterized by common clinical symptoms and a similar genetic background .Systemic Lupus Erythematous (SLE) is a chronic connective tissue disease characterized by a multi-system inflammatory disorder with immune system imbalance .Systemic sclerosis (SSc) is an immune-mediated rheumatic disease characterized by fibrosis of the skin and internal organs as well as vasculopathy . Nutritional status has been widely related to immunity; under-nutrition is associated with immunosuppression and increased susceptibility to infection whereas over-nutrition is associated with low-grade chronic inflammation increasing the risk and affecting the prognosis in metabolic, cardiovascular, and autoimmune diseases . Patients with rheumatic diseases are prone to develop malnutrition as their medications often affect appetite, nutrient absorption and digestion.Despite the high incidence of malnutrition and its consequences, there is no universally accepted definition for diagnosing nutritional deficiencies, and nutritional assessment still relies on analyses of a combination of several anthropometric, biochemical, immunological, functional and body composition data, in addition to dietary intake and the evaluation of clinical status. Four malnutrition diagnostic tools are currently used in adults: Subjective Global Assessment (SGA) ; Mini Nutritional Assessment (MNA) ; Academy of Nutrition and Dietetics/American Society for Parenteral and Enteral Nutrition malnutrition consensus characteristics; and Global Leadership Initiative on Malnutrition criteria. Certain objective nutritional assessment indices reflect the immune nutritional status of patients, such as the prognostic nutritional index (PNI) ; and the nutritional risk index (NRI) which are calculated using serum albumin level and lymphocyte count, were found to be related to the nutritional status and disease activity in SLE patients .