Optimal Blood Glucose Control During 18 Years Preserves Peripheral Nerve Function in Patients With 30 Years’ Duration of Type 1 Diabetes

Jakob R. Larsen; Hans Sjoholm; Kristian F. Hanssen; Leiv Sandvik; Tore J. Berg; Knut Dahl-Jorgensen

doi:10.2337/diacare.26.8.2400

Pathophysiology/Complications

Optimal Blood Glucose Control During 18 Years Preserves Peripheral Nerve Function in Patients With 30 Years’ Duration of Type 1 Diabetes

Jakob R. Larsen, MD1 2,
Hans Sjoholm, MD, PHD3,
Kristian F. Hanssen, MD, PHD1 4,
Leiv Sandvik, PHD5,
Tore J. Berg, MD, PHD1 4 and
Knut Dahl-Jorgensen1 2

¹Diabetes Research Center, Aker and Ulleval University Hospitals, Oslo, Norway
²Pediatrics Department, Ulleval University Hospital, Oslo, Norway
³Neurophysiology Department, Ulleval University Hospital, Oslo, Norway
⁴Endocrinology Department, Aker University Hospital, Oslo, Norway
⁵Center for Clinical Research, Ulleval University Hospital, Oslo, Norway

Address correspondence and reprint requests to Jakob R. Larsen, MD, Departement of Pediatrics, Aker and Ullevaal Diabetes Research Center, Ullevaal University Hospital, Oslo, Norway 0407. E-mail: j.r.larsen{at}ioks.uio.no

Diabetes Care 2003 Aug; 26(8): 2400-2404. https://doi.org/10.2337/diacare.26.8.2400

Article Figures & Tables

Tables

Table 1—

Demographic data in 1999 at 18-year follow-up in groups according to tertiles of mean HbA_1c over 18 years

	HbA_1c ≤7.8%	HbA_1c >7.8 and <8.4%	HbA_1c ≥8.4%
n	13	11	15
Sex distribution: men/women	6/7	8/3	9/6
Age (range)	43 (35–53)	42.5 (36–58)	43 (38–53)
Duration of diabetes (years)	29.5 ± 3.5	28.4 ± 3.6	32 ± 5
HbA_1c over 18 years (%)	7.3 ± 0.4	8.1 ± 0.1	9.1 ± 0.9
HbA_1c (%)	8.0 ± 0.8	8.6 ± 1.0	9.4 ± 1.5
Systolic blood pressure (mmHg)	128 ± 12	133 ± 21	126 ± 11
Diastolic blood pressure (mmHg)	79 ± 11	85 ± 9	77 ± 8
BMI (kg/m²)	22 ± 2	23 ± 2	23 ± 6
Total cholesterol (mmol/l)	5.4 ± 0.8	5.2 ± 0.5	5.4 ± 0.7
LDL cholesterol (mmol/l)	3.1 ± 0.9	3.1 ± 0.6	3.2 ± 0.8
HDL cholesterol (mmol/l)	2.0 ± 0.3	1.7 ± 0.3	1.6 ± 0.4
Triglycerides (mmol/l)	0.7 ± 0.2	1.0 ± 0.3	1.4 ± 1.6
Total cholesterol/HDL cholesterol ratio	2.8 ± 0.7	3.2 ± 0.7	3.5 ± 1.0
Microalbuminuria	0	1	3
Overt nephropathy	0	0	2
Current smokers	0	6	6
Patients on antihypertensive treatment	2	2	3
Patients on lipid-lowering medication	0	0	5

Data are means ± 1 SD.

Table 2—

Nerve function in 1982, 1990, and 1999 for tertiles of HbA_1c

HbA_1c tertiles	HbA_1c ≤ 7.8% (n = 13)	HbA_1c 7.9%–8.3% (n = 11)	HbA_1c ≥ 8.4% (n = 15)
Sensory sural NCV in 1982	51 m/s (4)	49 m/s (5)	47 m/s (7)
Sensory sural NCV in 1990	45 m/s (5)	43 m/s (5)	39 m/s (7)
Sensory sural NCV in 1999	44 m/s (10)	44 m/s (11)	34 m/s (15)†
Number of patients with undetectable sural NCV in 1999	1	1	5
Sensory sural NAPA in 1982	7.7 μV (5)	8.3 μV (3)	7.5 μV (3)
Sensory sural NAPA in 1990	8.3 μV (4)	6.7 μV (2)	5.9 μV (4)
Sensory sural NAPA in 1999	9.8 μV (9)	4.8 μV (4)*	3.4 μV (4)†
Motor tibial NCV in 1982	48 m/s (5)	46 m/s (5)	47 m/s (7)
Motor tibial NCV in 1990	42 m/s (3)	43 m/s (4)	38 m/s (5)
Motor tibial NCV in 1999	43 m/s (6)*	43 m/s (4)	31 m/s (11)†
Number of patients with undetectable tibial NCV in 1999	0	0	4
Tibial NAPA in 1999	4.9 mV (3)	4.9 mV (2)	2.6 mV
Motor peroneal NCV in 1982	44 m/s (4)	46 m/s (4)	41 m/s (4)
Motor peroneal NCV in 1990	42 m/s (2)	44 m/s (4)	38 m/s (5)
Motor peroneal NCV in 1999	41 m/s (4)	42 m/s (4)	35 m/s (8)*
Number of patients with undetectable peroneal NCV in 1999	0	0	1
NAPA peroneal nerve in 1999	2.7 mV (1)	2.9 mV (1)	1.7 mV (1)

Data are means ± 1 SD.
*
↵* P < 0.05;
†
↵† P < 0.01.

Table 3—

Number of patients with none or one nerve with NCVs under the lower limit of the reference value and two or more nerves with NCVs under the lower limit of the reference value with patients grouped according to tertiles of mean HbA_1c over 18 years

NCV:
Tertiles for HbA_1c	None or one nerve below references for NCV(a)	Minimum two nerves below references for NCV
HbA_1c < 7.8% (n = 13)	12 (92%)	1 (8%)
HbA_1c 7.9–8.4% (n = 11)	10 (91%)	1 (9%)
HbA_1c ≥ 8.4% (n = 15)	8 (53%)	7 (47%)

NAPA:
Tertiles for HbA_1c	None or one nerve below references for NAPA(b)	Minimum two nerves below references for NAPA
HbA_1c <7.8% (n = 13)	10 (77%)	3 (23%)
HbA_1c 7.9–8.4% (n = 11)	8 (73%)	3 (27%)
HbA_1c ≥8.4% (n = 15)	8 (53%)	7 (47%)