Subclinical protein malnutrition in irritable bowel syndrome: assessment by retinol-binding protein (RBP) and thyroxine-binding pre-albumin (TBPA).

We have assessed the nutritional status of 31 patients with irritable bowel syndrome (IBS) and 75 control subjects by anthropometry (height, weight, mid-arm circumference, biceps, triceps and subscapular skinfolds) and three plasma proteins: albumin, retinol-binding protein (RBP), and thyroxine-binding pre-albumin (TBPA). There was no significant difference between the patients and controls for any of the anthropometric measurements, but mean (+/- s.d.) plasma concentrations of RBP and TBPA were significantly lower in patients with IBS, 7.21 +/- 2.77 mg/dl (P less than 0.01); and 26.57 +/- 7.33 mg/dl, (P less than 0.001) respectively than in the control group, 8.85 +/- 2.56 mg/dl and 32.71 +/- 6.30 mg/dl. We conclude that patients with IBS may have subclinical protein deficiency in the absence of demonstrable organic bowel disease.