Table 1.

Characteristics of included studies

Author, year	Journal	Source of study population	Method for diagnosing CAN	Inclusion criteria	Number of participants	Mean follow-up duration (years)
Stella 20003	Journal of Diabetes and its Complications	Pittsburgh Epidemiology of Diabetes Complications Prospective Study (EDC Study)	Heart rate response to deep breathing	Patients with type 1 diabetes	373	4.7
Witte 200523	Diabetologia	Part of the EURODIAB Prospective Complications Study	Loss of heart rate variability or postural hypotension on standing	Patients with type 1 diabetes	956	7.3
Mogenson 201221	Diabetes	Type 1 diabetic patients registry	CAN was defined as two or more abnormal tests: heart rate variability during deep breathing, Valsalva ratio, lying-to-standing test and blood pressure response to standing up	Inclusion criteria were type 1 diabetes according to American Diabetes Association criteria of at least 10 years' duration, age between 18 and 75 years and HbA1C, 10%. Exclusion criteria were albuminuria (urinary albumin-to-creatinine ratio 30 mg/g; elevated S-creatinine 120 mmol/L), untreated hypertension (0.140/85 mm Hg) and electrocardiographic signs or clinical symptoms of heart disease	56	Not reported
Orlov 201522	Clinical Journal of American Society of Nephrology	The First Joslin Kidney Study	Heart rate variability	Patients with type 1 diabetes at the Joslin Diabetes Center	370	14

CAN, cardiac autonomic neuropathy.