Micronutrient antioxidant status in patients with primary Raynaud's phenomenon and systemic sclerosis.

OBJECTIVE

To investigate the possibility that micronutrient antioxidant status is an important factor in determining the severity of Raynaud's phenomenon (RP) and in differentiating between patients with primary Raynaud's phenomenon (PRP) and those in whom Raynaud's is secondary to systemic sclerosis (SSc).

METHODS

Four micronutrient antioxidants (selenium, vitamin E, beta-carotene and ascorbic acid) and 2 "markers" of free radical associated activity were assayed in peripheral blood from 10 patients with PRP, 9 with limited cutaneous SSc (ISSc), 9 with diffuse SSc (dSSc) and 15 healthy control subjects.

RESULTS

Plasma ascorbic acid was reduced in all 3 groups of patients: median level 10.6 mg/l in controls, 4.8 mg/l in PRP (p < 0.01), 2.5 mg/l in ISSc (p < 0.01) and 6.8 mg/l in dSSc (p < 0.05). A reduction in serum selenium was especially found in dSSc (median 75 micrograms/l compared to 100 micrograms/l in controls, p < 0.05). In keeping with these deficiencies, the serum concentration of 9, 11, linoleic acid was elevated in RP patients: median values for the molar ratio of the isomer to the parent fatty acid were 1.91% in controls, 3.70% in ISSc (p < 0.05) and 3.85% in dSSc (p < 0.01). Smoking patients showed lower levels of ascorbic acid and higher levels of the linoleic isomer than nonsmokers.

CONCLUSION

Deficiencies of ascorbic acid and selenium may predispose towards irreversible tissue injury in RP patients and cigarette smoke may be an independent risk factor. Micronutrient antioxidant supplements may be of therapeutic value.