Olga Lamacchia1, Andrea Fontana2, Antonio Pacilli3, Massimiliano Copetti4, Stefania Fariello1, Monia Garofolo5, Giuseppe Penno5, Vincenzo Trischitta6, Salvatore De Cosmo7, Mauro Cignarelli8. 1. Unit of Endocrinology and Diabetology, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy. 2. Unit of Biostatistics, Scientific Institute "Casa Sollievo della Sofferenza", San Giovanni Rotondo, Italy. 3. Unit of Internal Medicine, Department of Medical Sciences, Scientific Institute "Casa Sollievo della Sofferenza", San Giovanni Rotondo, Italy. 4. Unit of Biostatistics, Scientific Institute "Casa Sollievo della Sofferenza", San Giovanni Rotondo, Italy. Electronic address: m.copetti@operapadrepio.it. 5. Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy. 6. Research Unit of Diabetes and Endocrine Diseases, Scientific Institute "Casa Sollievo della Sofferenza", San Giovanni Rotondo, Italy; Mendel-Laboratory, Scientific Institute "Casa Sollievo della Sofferenza", San Giovanni Rotondo, Italy; Department of Experimental Medicine, "Sapienza" University of Rome, Rome, Italy. 7. Unit of Internal Medicine, Department of Medical Sciences, Scientific Institute "Casa Sollievo della Sofferenza", San Giovanni Rotondo, Italy. Electronic address: s.decosmo@operapadrepio.it. 8. Unit of Endocrinology and Diabetology, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy. Electronic address: mauro.cignarelli@unifg.it.
Abstract
BACKGROUND AND AIMS: High levels of serum uric acid (SUA) are associated with increased mortality risk in the general population. Contrasting results are available in people with diabetes. The aim of our study was to investigate the association and its functional form between SUA and all cause-mortality in patients with type 2 diabetes mellitus (T2DM). METHODS: We studied three cohorts of patients with T2DM: Gargano Mortality Study, Foggia Mortality Study, Pisa Mortality Study. All-cause mortality rate was the end point of this study. RESULTS: The most reliable relationship between SUA levels and all-cause mortality rate was quadratic, with such model being well approximated by SUA tertiles. Both tertiles 1 and 3 were at higher risk of mortality as compared to tertile 2: Hazard Ratio (HR) [95% Confidence Interval (CI)] = 1.34 (1.07-1.68) and 1.61 (1.29-1.99), respectively. In the pseudo-sample, created from the real pooled sample, the best relationship between SUA and all-cause mortality rate was quadratic. In a tree-based Recursive Partitioning and Regression Tree analysis two subgroups at increased risk of mortality were identified, namely those with SUA levels ≥7.28 mg/dl and with SUA levels <4.16 mg/dl as compared to patients with intermediate SUA levels (i.e. 4.16-7.28), thus providing further evidence on the J-shaped relationship between SUA levels and mortality rate. CONCLUSIONS: SUA was not linearly associated with all-cause mortality rate in patients with T2DM. For clinical and public health purposes such association is J-shaped.
BACKGROUND AND AIMS: High levels of serum uric acid (SUA) are associated with increased mortality risk in the general population. Contrasting results are available in people with diabetes. The aim of our study was to investigate the association and its functional form between SUA and all cause-mortality in patients with type 2 diabetes mellitus (T2DM). METHODS: We studied three cohorts of patients with T2DM: Gargano Mortality Study, Foggia Mortality Study, Pisa Mortality Study. All-cause mortality rate was the end point of this study. RESULTS: The most reliable relationship between SUA levels and all-cause mortality rate was quadratic, with such model being well approximated by SUA tertiles. Both tertiles 1 and 3 were at higher risk of mortality as compared to tertile 2: Hazard Ratio (HR) [95% Confidence Interval (CI)] = 1.34 (1.07-1.68) and 1.61 (1.29-1.99), respectively. In the pseudo-sample, created from the real pooled sample, the best relationship between SUA and all-cause mortality rate was quadratic. In a tree-based Recursive Partitioning and Regression Tree analysis two subgroups at increased risk of mortality were identified, namely those with SUA levels ≥7.28 mg/dl and with SUA levels <4.16 mg/dl as compared to patients with intermediate SUA levels (i.e. 4.16-7.28), thus providing further evidence on the J-shaped relationship between SUA levels and mortality rate. CONCLUSIONS:SUA was not linearly associated with all-cause mortality rate in patients with T2DM. For clinical and public health purposes such association is J-shaped.