The Long-Term Effects of Self-Management Education for Patients With Type 2 Diabetes on Glycemic Control: Response to Norris et al.

doi:10.2337/diacare.25.11.2115

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Letters: Comments and Responses
Letter

The Long-Term Effects of Self-Management Education for Patients With Type 2 Diabetes on Glycemic Control

Response to Norris et al.

Hirohito Sone, MD, PhD, FACP¹, Hideki Ito, MD, PHD², Yasushi Saito, MD, PHD³, Hidetoshi Yamashita, MD, PHD⁴, Shun Ishibashi, MD, PHD⁵, Shigehiro Katayama, MD, PHD⁶, Ryuzo Abe, MD, PHD⁷, Yasuo Ohashi, PHD⁸, Yasuo Akanuma, MD, PHD⁹, Nobuhiro Yamada, MD, PHD¹ and Japan Diabetes Complication Study Group

¹ Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Japan
² Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan
³ Second Department of Interenal Medicine, School of Medicine, Chiba University, Chiba, Japan
⁴ Department of Ophtalmology, School of Medicine, Yamagata University, Yamagata, Japan
⁵ Department of Internal Medicine, Jichi Medical College, Tochigi, Japan
⁶ Fourth Department of Internal Medicine, Saitama Medical College, Saitama, Japan
⁷ Ohta Nishinouchi Hospital, Koriyama, Fukushima, Japan
⁸ Department of Biostatistics/Epidemiology, School of Health Sciences and Nursing, University of Tokyo, Tokyo, Japan
⁹ Institute for Diabetes Care and Research, Asahi Life Foundation, Tokyo, Japan

We read with interest the recently published meta-analysis byNorris et al. (1), which focuses on the effects of diabetesself-management education (DSME) on glycemic control in adultpatients with type 2 diabetes. They report that this interventiondecreases patients’ GHb levels by 0.76% at immediate follow-up,by 0.26% at the 1- to 3-month follow-up and by 0.26% at $>=$ 4 monthsof follow-up. They conclude in both this meta-analysis and theirprevious systemic review (2) that DSME alone moderately butsignificantly improves GHb levels in the short term but thatits long-term effects still need to be determined in a studyof randomized controlled intervention.

As part of the Japan Diabetes Complications Study (JDCS), wehave been evaluating the long-term effects of DSME for >5years in 2,205 adult patients with type 2 diabetes. Our studyis longer and involves more patients than any of the trialsincluded in the meta-analysis by Norris et al. Ours is a randomized,controlled, multicenter, intervention trial that aims to evaluatethe effects of DSME. The trial involves 59 institutes specializingin diabetes care, and the 3-year interim report will be publishedshortly (3). In brief, we randomly allocated patients with previouslydiagnosed type 2 diabetes and HbA_1c levels of $>=$ 6.5% into eitheran intervention (INT) group or a control (CON) group. The patientsin the CON group received regular conventional care before orduring the study period. Although changes in medication werenot restricted in either group, there were no significant differencesin terms of therapeutic contents between the CON and INT groupseven after 3 years. The patients in the INT group received DSME,which comprised all of the categories that Norris et al. includedin their meta-analysis (1) and consisted mainly of intensivelifestyle management at each outpatient clinic visit and frequenttelephone counseling by trained diabetes educators. Our resultsshow that there are small but significant differences in HbA_1clevels between the INT and CON groups that are still maintained3 years after the start of intervention (CON group 7.78 ±1.27% vs. INT group 7.62 ± 1.20%, P = 0.0023). Althoughthe difference between the two groups is small, it should benoted that a bias arising from variations in the techniquesof GHb measurement, as discussed by Norris et al. (1), doesnot exist in Japan, where a highly standardized assay is usedthroughout the country. Therefore, the difference in the JDCSstudy is likely to be a realistic measurement of the effectof DSME intervention.

The improvement in GHb levels of <1% seen in the resultsof the meta-analysis (1), as well as in our longer-term trial(3), seems to be clinically trivial and disappointing as comparedwith medical interventions (i.e., drugs or insulin). As Norriset al. discuss in their article (1), however, it is still clinicallymeaningful because each 1% reduction in HbA_1c levels over 10years has been shown to be associated with a 37% reduction inthe risk of microvasular complications in the U.K. ProspectiveDiabetes Study (UKPDS) (4). We expect that further meta-analysesregarding differences in long-term costs and the patients’quality of life between DSME and medications that lower GHblevels will be carried out. In the JDCS, however, the long-termeffects on lifestyle brought about by DSME and the cost of itsimplementation are already under analysis.

In summary, on the basis of the large-scale JDCS trial, we canconclude that the moderate but significant improvement effectedby DSME on the glycemic control of adult patients with type2 diabetes is maintained even in the long term.

Footnotes

Address correspondence to Nobuhiro Yamada, MD, PhD, Instituteof Clinical Medicine, University of Tsukuba, 1-1-1 Tennodai,Tsukuba, Ibaraki, Japan 305-8575. E-mail: jdcstudy{at}md.tsukuba.ac.jp.

References

Norris SL, Lau J, Smith SJ, Schmid CH, Engelgau MM: Self-management education for adults with type 2 diabetes: a meta-analysis of the effect on glycemic control. Diabetes Care 25:1159–1171, 2002[Abstract/Free Full Text]
Norris SL, Engelgau MM, Narayan KM: Effectiveness of self-management training in type 2 diabetes: a systematic review of randomized controlled trials. Diabetes Care 24:561–587, 2001[Abstract/Free Full Text]
Sone H, Katagiri A, Ishibashi S, Abe R, Saito Y, Murase T, Yamashita H, Yajima Y, Ito H, Ohashi Y, Akanuma Y, Yamada N, JDCStudy Group: Effects of lifestyle modifications on patients with type 2 diabetes: the Japan Diabetes Complications Study (JDCS) study design, baseline analysis and three year-interim report. Horm Metab Res, In Press.
Stratton IM, Adler AI, Neil HA, Matthews DR, Manley SE, Cull CA, Hadden D, Turner RC, Holman RR: Association of glycaemia with macrovascular and microvascular complications of type 2 diabetes (UKPDS 35): prospective observational study. Br Med J 321:405–412, 2000[Abstract/Free Full Text]