Main results

We investigated risk factors and care in two primary prevention cohorts in European people living with T1D. First, we found similar results in Germany and France, considering risk factors, with better control in females than males for blood pressure, HDL-cholesterol, triglyceride levels, and fewer smoking habits. Second, we observed clinical inertia in both countries concerning the prescription of statin in case of LDL-cholesterol above the target and ACEi-ARB in case of microalbuminuria. Third, this inertia was more evident in females than males in Germany.

Glucose, weight and blood pressure control, smoking: a better cardiovascular profile in females than males

Around one-quarter of the participants of DPV and SFDT1 had an HbA1c < 7.0%, in agreement with recent data from the United States [13, 14]. As others [13, 15,16,17,18], we have found that females had similar HbA1c levels and at target as males. Females were reported to be less likely to achieve an HbA1c < 7.0% than males in some studies [14, 19, 20]. On the contrary, a publication from the entire DPV registry had shown that, in adult patients, women constantly showed lower HbA1c values than men from 2004 to 2018 [21]. The different DPV results found in the current study may be explained by the restricted selection criteria (2020–2022 data, participants in primary prevention, participating specialized centres located in Germany defined by including more than 100 patients) and a lower statistical power than in the previous study [21]. Note that the use of CSII was higher in women than in men in our two cohorts, as previously shown [17, 20, 21].

We report overweight or obesity in more than one-half of the participants of DPV and SFDT1, as recently reported in the United States [13, 14]. We found in Germany that females were more likely than males to have a normal weight, as in recent data from the United States [14]. The inverse had been shown in earlier studies in Scotland [22] and Italy [23].

Blood pressures were at target in around 80% of participants of DPV and SFDT1. The latter percentage was around 33% in the Diabetes Control and Complications Trial (DCCT) [14]. As previously reported [13,14,15, 17,18,19,20], we have observed lower DBP and SBP levels in females than in males. In the SFDT1 cohort, fewer antihypertensive treatments were reported in females than males, as shown in many former studies [13,14,15, 17,18,19,20]. Finally, as previously reported [22, 23], females were less likely to be active smokers.

Lipid control is better in females than in males

In people living with T1D, higher HDL-cholesterol and lower triglyceride levels are usually described in females than males [14,15,16, 20, 22, 23]. We found the same results in the present study in Germany and France. We also found lower levels of LDL-cholesterol in females than males, and this was only found in one Finnish study [19], while levels were similar in both sex in others [14,15,16, 20, 22, 23].

LDL-cholesterol was at target in around 80% of DPV participants and in 70% of SFDT1 participants, respectively. This percentage has not been previously described in the literature in primary prevention individuals with T1D. To note, the longitudinal rate of achieving LDL cholesterol level < 70 mg/dl was recently reported to be 31.5% in women and 32.2% in men in the DCCT/Epidemiology of Diabetes Interventions and Complications (EDIC) study [14]; and 30.6% and 32.0%, respectively, in a Dutch registry [18].

Clinical inertia when LDL-cholesterol is above the target and in case of microalbuminuria

We report a very low rate of statin treatment (13% in DPV and 15% in SFDT1) in patients with LDL-cholesterol ≥ 3.4 mmol/L. This may be due to the absence of randomized controlled trials in patients with T1D and the uncertainty of the benefit/risk balance in the long term in often young patients [4, 24]. However, a study of more than 24,000 patients in primary prevention and with T1D showed that, over 6 years, those treated with lipid-lowering treatment as compared to those who were untreated had a hazard ratio of 0.56 (95% confidence interval 0.48–0.64) for death from any cause and 0.85 (0.74–0.97) for coronary heart disease [25].

Clinical inertia was also observed, to a lesser extent, for ACEi-ARB use in the case of albuminuria (around 70% in DPV and 35% in SFDT1). This is an issue as it is associated with a 50% reduction in the risk of a composite of death, dialysis, and renal transplantation [26]. The results show that cardiovascular prevention is still insufficient in the DPV and SFDT1 centres. To note, clinical inertia for statin and ACEi-ARB therapy, when recommended, was more prominent in females than males in DPV but not in SFDT1. Statin prescription was previously shown to be better applied in males than females with T1D in the United States [17] and Italy [20].

Strengths and limitations

This analysis presents real-world data from two large multicenter independent cohorts over the three recent years, covering a large cardiovascular parameter set. One of the main limitations of this study is the comparison of two different cohorts with distinct clinical data sources. We report the results and treatment for the patients at the entry in the recruiting centres for SFDT1. Data in the SFDT1 study are mainly from University Hospitals at the current time, and as such, data may not be transferable for all French patients living with T1D. To obtain a comparable population, we included in DPV only adults treated in large diabetes centres (> 100 patients) participating in the DPV initiative. This population may also not represent all adults with T1D in Germany. In addition, the following data were not assessed in the current work: completion of screening for risk factors [18, 20], physical activity [13] and cardiac autonomic neuropathy [27]. Finally, we did not separate females before and after 50 years of age, although menopause may interfere with cardiovascular risk also in T1D [1,2,3]. In DPV, lipids may not have been measured at the fasting state.

Perspectives

Before they were excluded from our study samples, the percentage of DPV and SFDT1 participants with a cardiovascular history was 13.8% in DPV (females 11.8% and males 15.6%) and 6.3% in SFDT1 (females 3.5% and males 8.7%). Although the patients who were included had the same age and sex ratio in DPV and SFDT1 studies, the higher rate of cardiovascular history in DPV may reflect the moderate cardiovascular risk in Germany and the low one in France [28]. This percentage is lower than older reports [7, 29] but is in line with recent data [30]. This is likely due to improved cardiovascular management in the T1D population [31,32,33]. We also have confirmed that males had a higher prevalence of cardiovascular disease than females in our two cohorts [6, 7], although they had very similar age and diabetes duration.

We observed that cardiovascular prevention could be improved in people living with T1D, and we think such a benchmark if repeated annually, could help caregivers improve their performances.

As reported in primary care [34], we observed, especially in DPV, disparities in care by sex. From a medical perspective, this may be due to a lower perception of cardiovascular risk and a lower cardiovascular benefit of statin in females than males [35]. From a patient's perspective, females may have the perception of a lower cardiovascular risk. They also have been described to be more prone to medication non-adherence [36]. This also might be due to therapies stopped during pregnancy and not prescribed thereafter, but this does not explain the difference in Germany and France, as mean age was similar for women in both countries here.