Effects of cancer comorbidity on disease management: making the case for diabetes education (a report from the SOAR program).

Individuals with type II diabetes have an increased risk of cancer diagnosis (relative risk [RR]=1.12-2.50) and mortality (RR=1.4) compared to normoglycemic individuals. Biologic mechanisms, including mitogenic effects of insulin, hyperglycemia, and increased oxidative stress, as well as behavioral factors (eg, difficulty managing the comorbidity) may explain the elevated risk. To investigate the effects of the comorbidity on disease management, the authors compared diabetes education utilization in individuals with diabetes-cancer co-morbidity to utilization by individuals with diabetes in the absence of cancer. The effect of diabetes education on outcomes was further assessed in the subset of individuals with diabetes-cancer comorbidity. Administrative claims data were used for this analysis. The study population included individuals >60 years of age and members of both commercial and Medicare Advantage health plans from a private national database of payer data, but excluded Medicare fee for service and Medicaid patients. Most of these individuals were eligible to receive reimbursement for diabetes education. Diabetes education utilization was identified using procedure codes. Outcomes were assessed for a 3-year time period. There was little difference in diabetes education utilization between individuals with diabetes in the absence of cancer (3.8% utilization) and those with diabetes-cancer comorbidity (3.5% utilization). Individuals who receive diabetes education are more likely to have multiple HbA1c tests per year, fewer emergency department visits, fewer hospital admissions, and lower care-associated costs (except for outpatient and pharmacy averages). When diabetes coexists with cancer, management of diabetes often lags, making diabetes education an imperative.

Multifunctional roles of the conserved Arg residues in the second region of homology of p97/valosin-containing protein.

The 97-kDa molecular chaperone valosin-containing protein (VCP) belongs to a highly conserved AAA family and forms a hexameric structure that is essential for its biological functions. The AAA domain contains highly conserved motifs, the Walker A, Walker B, and the second region of homology (SRH). Although Walker A and B motifs mediate ATP binding and hydrolysis, respectively, the function of the SRH in VCP is not clear. We examined the significance of the SRH in VCP, especially the conserved Arg(359) and Arg(362) in the first AAA domain, D1 and Arg(635) and Arg(638) in the second AAA domain, D2. We show that Arg(359) and Arg(362) in D1 are critical for maintaining the hexameric structure and the ability to bind the polyubiquitin chains. Although the rest of the tested SRH mutants retain the hexameric structure, all of them exhibit severely reduced ATPase activity. Tryptophan fluorescence analysis showed that all of the tested mutants can bind to ATP or ADP. Thus, the reduced ATPase activity likely results from the hampered communications among protomers during hydrolysis. Moreover, when the ATPase-defective mutant R635A or R638A is mixed with the Walker A mutant of D2, the ATPase activity is partially restored, suggesting that Arg(635) and Arg(638) can stimulate the ATPase activity of the neighboring protomer. Interestingly, mutation of Arg(359) and Arg(362) uncouples the inhibitory effect of p47, a VCP co-factor, on the ATPase activity of VCP. Therefore, the Arg residues allow D1 to take on a specific conformation that is required for substrate binding and co-factor communications. Taken together, these results demonstrate that the conserved Arg residues in the SRH of both D1 and D2 play critical roles in communicating the conformational changes required for ATP hydrolysis, and SRH in D1 also contributes to substrate binding and co-factor communications.