{"doi":"10.2337/dc22-1763","title":"Proinsulin–to–C-Peptide Ratio as a Marker of β-Cell Function in African American and European American Adults","abstract":"OBJECTIVE: The primary purpose of the current study was to test the hypothesis that the proinsulin-to-C-peptide (PI-to-CP) ratio, as an index of proinsulin secretion, would be higher and associated with indices of β-cell function in African American adults relative to European American adults without type 2 diabetes. RESEARCH DESIGN AND METHODS: Participants were 114 African American and European American adult men and women. A 2-h oral glucose tolerance test was conducted to measure glucose, insulin, C-peptide, and proinsulin and derive indices of β-cell response to glucose. The Matsuda index was calculated as a measure of insulin sensitivity. The disposition index (DI), the product of insulin sensitivity and β-cell response, was calculated for each phase of β-cell responsivity. Pearson correlations were used to investigate the relationship of the PI-to-CP ratio with each phase of β-cell response (basal, Φb; dynamic, Φd; static, Φs; total, Φtot), disposition indices (DId, DIs, DItot), and insulin sensitivity. Multiple linear regression analysis was used to evaluate independent contributions of race, BMI, and glucose tolerance status on PI-to-CP levels before and after adjustment for insulin sensitivity. RESULTS: African American participants had higher fasting and 2-h PI-to-CP ratios. The fasting PI-to-CP ratio was positively associated with Φb, and the fasting PI-to-CP ratio and 2-h PI-to-CP ratio were inversely associated with DId and insulin sensitivity only in African American participants. CONCLUSIONS: The PI-to-CP ratio could be useful in identifying African American individuals at highest risk for β-cell dysfunction and ultimately type 2 diabetes.","journal":"Diabetes Care","year":2023,"id":342272,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":14,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9478,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":234130,"name":"Francesca Piccinini","orcid":null,"position":1,"is_corresponding":false},{"id":365924,"name":"Lauren A. Fowler","orcid":"0000-0001-8850-0058","position":2,"is_corresponding":false},{"id":269614,"name":"W. Timothy Garvey","orcid":null,"position":3,"is_corresponding":false},{"id":321518,"name":"Barbara A. Gower","orcid":"0000-0001-8461-4613","position":4,"is_corresponding":false},{"id":723365,"name":"Catharine A Couch","orcid":"0000-0002-4568-8609","position":0,"is_corresponding":true}],"reference_count":39,"raw_metadata":null,"created_at":"2026-07-19T01:11:12.506815Z","pmid":"36787895","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}