A perspective on sporadic inclusion-body myositis: the role of aging and inflammatory processes.

Sporadic inclusion-body myositis (sIBM) is an age-related condition manifested after midlife. This review points out salient features of sIBM that are shared with normal aging in muscle and with inflammatory changes in vascular atheromas and senile plaques of Alzheimer disease (AD). The amyloid precursor protein (APP) and derived Abeta peptides are found in both AD and sIBM. Because transgenic expression of human APP induces sIBM like changes, it is of potential interest that an inducer of APP, IL-1, increases during aging in mouse muscle. Because various subsets of the usual aging changes in aging brain, muscle, and vessels can be attenuated in rodents by caloric intake and possibly in humans by drugs with anti-inflammatory and anticoagulant activities, this study suggests that diet and inflammation may be useful experimental variations in exploring the pathogenesis of sIBM.