Table 1.
Summary of studies on prevalence of cardiac autonomic neuropathy
| Study | Diagnostic test | Criteria | Cutoffs | Prevalence (%) | Patients, n | DM type | Population | Ethnicity | Notes |
|---|---|---|---|---|---|---|---|---|---|
| O’Brien et al10 | 1. HRV response to rest 2. E:I ratio 3. Valsalva maneuver 4. 30:15 ratio 5. CV of HRV |
Two or more abnormal tests | HR responses below percentile 2.5 (abnormal) | 17 | 506 | T1DM | Mean age 45 years Diabetes duration 15 years |
NA | |
| Navarro et al11 | 1. E:I ratio 2. Valsalva ratio |
Two abnormal tests | 1. HRV ≥15 bpm 2. ≥1.43 |
65.9 | 545 | T1DM | Mean age 33.4 years Diabetes duration 19.4 years |
NA | |
| Chen et al12 | 1. E:I ratio 2. HRV during six consecutive breaths 3. 30:15 ratio 4. Valsalva maneuver 5. Postural drop |
Scoring 3 or more | 1. HRV <8 bpm (1) 2. HRV <7 bpm (2) 3. HRV <17 bpm (1) 4. HRV <13 bpm (1) 5. SBP fall >25 mmHg or DBP fall >10 mmHg |
60.6 | 612 | T2DM | Mean age 63.1 years Diabetes duration 10.4 years |
Data collected from a Taiwanese hospital | Numbers in parentheses represent score given to each CART |
| Kempler et al13 | 1. 30:15 ratio 2. SBP postural drop |
One abnormal test | 1. <1.04 2. Drop >20 mmHg |
36 | 3,010 | T1DM | Mean age 32.7 years Diabetes duration 14.7 years Mean HbA1c 6.7% |
Data collected in European countries | |
| Low et al14 | 1. Sudomotor axon-reflex test 2. HRV during Valsalva maneuver 3. SBP postural drop and 30:15 4. E:I ratio |
CASS ≥1 in two domains or ≥2 in one domain (sudomotor, cardiovagal, adrenergic) | CASS is 10-point score divided into adrenergic (0–4), sudomotor (0–3), and cardiovagal (0–3) No specific cutoffs were quoted in the paper |
54 (T1DM) 73 (T2DM) |
68 (T1DM) 134 (T2DM) |
T1DM T2DM |
Mean age 59 years HbA1c 7.4% (T1DM) and 7.2% (T2DM) |
T1DM – 100% white T2DM – 98% white |
Recruited from Rochester Diabetic Neuropathy Study; CASS corrected for confounding effects of age and sex |
| Pop-Busui et al15 | 1. E:I ratio 2. Valsalva maneuver 3. DBP postural drop |
Abnormal HRV combined with abnormal Valsalva ratio or DBP drop | 1. HRV <15 bpm 2. ≤1.5 3. Drop >10 mmHg |
29 (intensive-Tx group) 35 (conventional-Tx group) |
620 (intensive-Tx group) 591 (conventional-Tx group) |
T1DM | Mean age 47 years Diabetes duration 26 years HbA1c 7.9% (intensive), 7.8% (conventional) |
NA | Primary and secondary care |
| Eze et al17 | 1. Resting HR 2. Valsalva ratio 3. HRV to deep breathing 4. 30:15 ratio 5. Postural drop |
Score ≥3 out of 5 Borderline = 0.5 Abnormal = 1 |
1. ≥100 bpm (abnormal) 2. ≤1.1 (abnormal), 1.11–1.2 (borderline) 3. ≤10 bpm (abnormal), 11–14 bpm (borderline) 4. ≤1 (abnormal), 1.01–1.03 (borderline) 5. SBP ≥20 mmHg (abnormal), DBP ≥10 mmHg (abnormal) |
44.3 | 70 | T2DM | Mean age 55.76 years Diabetes duration 7.67 years Male 38.6% |
Nigerian | Secondary care |
| Tahrani et al18 | 1. E:I ratio 2. Valsalva ratio 3. 30:15 ratio 4. Postural drop |
Two or more abnormal tests | Abnormal values not given. except postural drop of SBP >20 mmHg or DBP >10 mmHg | 42.2 | 204 | T2DM | Mean age 59.5 years Diabetes duration 15 years Male 60.5% HBA1c 8.2% |
White European – 43.6% South Asian – 56.4% |
Secondary care |
| Lerner et al19 | 1. Valsalva maneuver 2. SBP postural drop 3. 30:15 ratio 4. E:I ratio |
Two or more abnormal tests | 1. <1.2 2. 10–29 mmHg (borderline), >30 mmHg (abnormal) 3. <1.03 4. HRV <10 bpm |
37 | 384 | T2DM | Mean age 57.6 years | Peru | Primary and secondary care |
| Mendivil et al20 | 1. E:I ratio 2. Valsalva maneuver 3. 30:15 ratio |
One or more abnormal or borderline tests | 1. HRV ≤10 (abnormal), 11–14 (borderline) 2. ≤1.1 (abnormal), 1.11–1.2 (borderline) 3. ≤1 (abnormal), 1.01–1.03 (borderline) |
68 | 154 | T2DM | Mean age 61.4 years Diabetes duration 12.2 years HbA1c 7.7% |
Latin American | Secondary care |
| Razanskaite-Virbickiene et al21 | 1. E:I ratio 2. 30:15 ratio 3. SBP postural drop 4. DBP change to isometric exercise |
Two or more abnormal tests | 1. ≤1.1 2. ≤1.1 3. Drop ≤20 mmHg 4. Drop ≤10 mmHg |
32.2 | 208 | T1DM | Mean age 20 years Diabetes duration 15.1 years HbA1c 9.46% |
Data collected from a Lithuanian–Swiss project | |
| Menon et al22 | 1. E:I ratio 2. 30:15 ratio 3. SBP postural drop 4. DBP change to isometric exercise |
One abnormal test = possible CAN Two abnormal tests = definite CAN |
1. 20–24 years, 1.17; 25–29, 1.15; 30–34, 1.13; 35–39, 1.12; 40–44, 1.1; 45–49, 1.08; 50–54, 1.07; 55–59, 1.06; 60–64, 1.04; 65–69, 1.03; 70–75, 1.02 2. <1.03 3. Drop >30 mmHg 4. Difference between highest and resting DBP of ≤15 mmHg |
31 (possible) 66.2 (definite) |
74 | T2DM | Mean age 61.1 years Diabetes duration 10.2 years HbA1c 8.9% |
NA | Secondary care |
| Tahrani et al23 | 1. E:I ratio 2. Valsalva ratio 3. 30:15 ratio 4. SBP and DBP postural drop |
Two or more abnormal tests | Abnormal values not given, except postural drop of SBP >20 mmHg or DBP >10 mmHg | 40.9 in both South Asians and Caucasians | 126 (South Asian) 140 (Caucasian) |
T2DM | Mean age 59.5 years (South Asians), 59.2 years (Caucasians) Diabetes duration 11 years (South Asian), 10.5 years (Caucasians) HbA1c 8% |
White Caucasian – 52.6% South Asian – 47.4% |
Secondary care |
Abbreviations: HRV, heart-rate variability; DM, diabetes mellitus; E:I, expiration:inspiration; CASS, composite autonomic severity score; CV, coefficient of variation; CART, cardiovascular reflex test; T1DM, type 1 DM; T2DM, type 2 DM; CAN, cardiac autonomic neuropathy; Tx, treatment; SBP, systolic blood pressure; DBP, diastolic blood pressure; NA, not applicable; HbA1c, glycated hemoglobin.