Association between skeletal muscle mitochondrial dysfunction and insulin resistance in patients with rheumatoid arthritis: a case-control study.

Background: Insulin resistance affects a substantial proportion of patients with rheumatoid arthritis (RA). Skeletal muscle mitochondrial dysfunction results in the accumulation of lipid intermediates that interfere with insulin signaling. We therefore sought to determine if lower oxidative phosphorylation and muscle mitochondrial content are associated with insulin resistance in patients with RA.

Fingernail and toenail clippings as a non-invasive measure of chronic cortisol levels in adult cancer survivors.

Purpose: Cancer survivors are at greater risk of comorbidities and functional decline due to physiological and psychological stress which can be measured by salivary cortisol. If saliva is used, multiple samples must be collected to accurately quantify long-term stress; however, fingernail (FN) and toenail (TN) clippings offer an opportunity to measure retrospective cortisol levels in a non-invasive manner.

Methods: Three sets of FN and TN clippings were collected at 12-month intervals in conjunction with saliva samples from cancer survivors (n = 109) participating in two clinical trials.