Data on the impact of peripheral artery disease and of type 2 diabetes mellitus on the risk of cardiovascular events

Here, we provide additional data addressing the individual and combined associations of type 2 diabetes (T2DM) and of peripheral artery disease (PAD) with future cardiovascular events in a prospective cohort study including 338 PAD patients and 711 patients who did not have PAD. Subgroup analyses regarding patient age as well as additional Cox regression models taking into account medications are presented. This data article is related to a research article titled “Single and combined effects of peripheral artery disease and of type 2 diabetes mellitus on the risk of cardiovascular events: a prospective cohort study” (Saely et al., 2018).


Subject area
Medicine, clinical research More specific subject area Vascular medicine, epidemiology Type of data Figure, tables How data were acquired National registries, blood pressure recordings, body weight and height measurements, standard laboratory procedures for the measurement of biochemical variables, review of patient registries; data were entered into Microsoft Access and evaluated using the software package SPSS 24.0 for Windows ( Value of the data The data presented here clarify the individual and combined associations of T2DM and of PAD with future cardiovascular events and thus help to better understand the cardiovascular risk associated with these entities.
The data presented here show that age does not significantly affect the impact of T2DM on cardiovascular event risk in patients with or in subjects without PAD and thus help to understand the role of age for the cardiovascular risk associated with T2DM and PAD.
The data presented here show that major cardiovascular medications do not significantly affect the associations between T2DM, PAD and cardiovascular events.
The data presented here highlight the very high cardiovascular risk of PAD patients, in particular of those who additionally have T2DM. They should stimulate future epidemiologic research and provide a rationale to specifically include these patients in intervention trials aiming to reduce cardiovascular events.

Data
The data presented here are related to a research article published separately by the same authors [1]. Data are shown (i) for age subgroups ( Fig. 1 and Table 1) and (ii) regarding Cox regression analyses adjusting for major cardiovascular medications (Table 2).

Experimental design, materials and methods
To obtain the present data, we enrolled 1049 subjects, including 338 with PAD and 711 without PAD at the Academic Teaching Hospital Feldkirch, Austria and at the Division of Angiology at the University Hospital Berne, Switzerland from September 2006 through January 2012.
As patients with PAD, we enrolled 338 Caucasian patients who were symptomatic for PAD and had an ankle brachial index o 0.9 or previous revascularization of peripheral arteries who underwent  routine duplex sonography and in whom PAD was verified by sonography. Patients with type 1 diabetes or with Fontaine stage IV were not enrolled. As subjects without PAD we enrolled individuals from a cohort of 711 consecutive Caucasian patients referred for coronary angiography for clinical reasons, in whom significant CAD with lumen narrowing Z50% was ruled out angiographically [2] and who neither at present nor in the past had any signs or symptoms of PAD such as intermittent limb claudication, history of PAD or peripheral revascularization, or ABI o0.9). Patients with a history of acute coronary syndromes within three months prior to baseline angiography and subjects with type 1 diabetes were not enrolled.
We recorded height and weight as well as waist and hip circumferences at baseline. Data on conventional cardiovascular risk factors such as a history of smoking, hypertension, established diabetes, and a family history of atherosclerotic disease were obtained by a standardized interview. Systolic as well as diastolic resting blood pressures were measured by the Riva-Rocci method in a sitting position at the day of hospital admission after a 1 h rest. To define hypertension we used the 2013 ESC/ESH guidelines [3], and we diagnosed type 2 diabetes according to 2018 ADA clinical practice recommendations [4].
The incidence of cardiovascular events and of death was recorded during follow-up. We annually collected time and cause of death from a national registry (Statistik Austria, Vienna, Austria) as well as from hospital registries and telephone contacts; data on non-fatal events were biannually obtained using standardized interviews.
As the primary endpoint, a composite consisting of coronary death (fatal myocardial infarction, sudden cardiac death, mortality from congestive heart failure due to CAD), fatal ischemic stroke, nonfatal myocardial infarction, non-fatal ischemic stroke, and need for revascularization coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), revascularization in the carotid or peripheral arterial beds or amputation at the lower extremities was used. Coronary angioplasty, bypass surgery, revascularizations of the peripheral arteries or amputation at the lower extremities were regarded as end points only if not scheduled as a consequence of the findings of the baseline examinations. We achieved a follow-up rate of 98.3%.
Our protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki, and the Ethics Committees of the Universities of Innsbruck and Berne approved it; written informed consent was given by all participants.
Venous blood samples were drawn after an overnight fast of at least 12 h and measurements of biochemical variables were performed from fresh serum samples, as described previously [5,6]. Serum levels of triglycerides, total cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) and cholesterol, C-reactive protein (CRP), and plasma glucose were measured on a Cobas Integra 800 s (Roche, Basel, Switzerland) and Haemoglobin A1c (HbA1c) by high-performance liquid chromatography on a Menarini-Arkray KDK HA 8140 s (Arkray KDK, Kyoto, Japan).
We tested differences in baseline characteristics for statistical significance with the Chi-squared and the Mann-Whitney U-tests for categorical and continuous variables, respectively. To compare differences in the cumulative incidence rates of cardiovascular events the Wilcoxon-Gehan statistic was applied. We derived adjusted hazard ratios for the incidence of first cardiovascular events from Cox proportional hazards models; continuous variables were z-transformed for these calculations. Data are given as mean (7 standard deviation) if not denoted otherwise. All statistical analyses were performed using the software package SPSS 24.0 for Windows (SPSS, Chicago, IL, USA).