Objective: Cardiovascular disease (CVD) is the major cause of mortality in type 1 diabetes (T1D). The objective of this study is to evaluate fibroblast growth factor 23 (FGF23) and calcium-phosphate metabolism in relation to cardiovascular risk factors in adults with and without type 1 diabetes.
Design/Methods: A case-control study was conducted using data from patients with T1D and age34 and sex matched controls without T1D from the Lifelines Cohort Study.
Results: We included 302 adults in the T1D group and 302 adults in the control group. Median age was 42yrs. Median HbA1c in the T1D group was 7.8%.
Median FGF23 in patients with T1D was not significantly different from controls. Females with T1D had significantly higher FGF23 than males with T1D (83.3 vs 69.3U/ml, p=0.002), this was not observed in controls. Serum phosphate, calcium, and alkaline phosphatase were higher and PTH was lower in patients with T1D, compared to controls (all p<0.001), all within normal range. In the T1D group, FGF23 was positively correlated with serum phosphate (p<0.001), alkaline phosphatase (p=0.01) and calcium (p=0.030), these correlations were not observed in controls. Median FGF23 was significantly higher in current smokers than in non-smokers with T1D ( 84.9 vs 73.5U/ml, p<0.05).
Conclusions: Serum calcium, phosphate and alkaline phosphatase were higher in patients with T1D than in controls and were positively correlated to FGF23 in patients with T1D. Current smokers with T1D had higher FGF23 than non-smokers with T1D. These findings may contribute to the increased risk of CVD in patients with T1D.