Volume 194 - Issue 9
Scurvy and stroke: is there an association?
Authors: Felicity J Rose and Jonathan P Whitehead
Med J Aust 2011; 194 (9): 486. || doi: 10.5694/j.1326-5377.2011.tb03070.x
Published online: 2 May 2011
Published online: 2 May 2011
To the Editor: We read with interest the recent letter by He and colleagues.1 The authors described a case of ischaemic stroke in a patient with scurvy and considered whether there was a connection between the two conditions. They referred to evidence that vitamin C deficiency may be a risk factor for cerebrovascular disease, but acknowledged that a direct causal link is unlikely to be established.
We propose adiponectin as the causal link between vitamin C deficiency and stroke. Adiponectin is an adipokine, secreted in multimers by adipose tissue, with insulin-sensitising, antiatherogenic and cardioprotective properties.2 A decrease in adiponectin levels — particularly the more biologically active, high molecular weight (HMW) multimers — is implicated in a number of disease states, such as obesity, type 2 diabetes, heart disease and some cancers. Adiponectin has also been reported to have cerebroprotective properties,3 and there is some evidence that levels may be reduced in patients with cerebrovascular disease.4
A recent study demonstrated that vitamin C supplementation increases the proportion of HMW adiponectin secreted from human adipocytes.5 Vitamin C levels are lower in obese and diabetic patients, and the patient reported by He et al had also been recently diagnosed with type 2 diabetes.
While scurvy is admittedly rare, He and colleagues noted that subclinical vitamin C deficiency is not uncommon in the general population (about 10%). We suggest that it would be worthwhile to assay plasma vitamin C levels and total and HMW adiponectin levels in patients presenting with cerebrovascular events, and to undertake prospective studies to determine whether vitamin C supplementation improves patients’ adiponectin levels. Increased HMW adiponectin levels could be explained, at least in part, by the role of vitamin C in the multimerisation of adiponectin.
Adiponectin levels are also reduced in other vascular conditions, such as ischaemic heart disease and peripheral vascular disease.4 As plasma vitamin C levels of patients with these diseases are also reduced, it is tempting to posit that vitamin C supplementation could have a role as a treatment, or even a prophylactic, in populations at risk of a range of adiponectin-related vascular diseases.
References
- He EY, Wang LW, Kiernan MC. Scurvy and stroke: is there an association? Med J Aust 2010; 193: 555-556. 0_CBBFIGII
- Whitehead JP, Richards AA, Hickman IJ, et al. Adiponectin — a key adipokine in the metabolic syndrome. Diabetes Obes Metab 2006; 8: 264-280. 0_CBBCCGGF
- Nishimura M, Izumiya Y, Higuchi A, et al. Adiponectin prevents cerebral ischemic injury through endothelial nitric oxide synthase dependent mechanisms. Circulation 2008; 117: 216-223. 0_pgfId-2308939
- Szmitko PE, Teoh H, Stewart DJ, Verma S. Adiponectin and cardiovascular disease: state of the art? Am J Physiol Heart Circ Physiol 2007; 292: H1655-H1663. 0_CBBCBGCA
- Rose FJ, Webster J, Barry JB, et al. Synergistic effects of ascorbic acid and thiazolidinedione on secretion of high molecular weight adiponectin from human adipocytes. Diabetes Obes Metab 2010; 12: 1084-1089. 0_CBBFEJDB