Response to Comment on: Keenan et al. (2010) Residual Insulin Production and Pancreatic ?-Cell Turnover After 50 Years of Diabetes: Joslin Medalist Study. Diabetes 2010;59:2846-2853.

2010·0.03 MB·English

by  Keenan, Hillary A.

ONLINELETTERSTOTHEEDITOR
Response to Comment on: Keenan et al. (2010) Residual
(cid:1)
Insulin Production and Pancreatic -Cell Turnover After
50 Years of Diabetes: Joslin Medalist Study. Diabetes
2010;59:2846–2853
Hillary A. Keenan, Susan Bonner-Weir, and George L. King
a mean of 55 years of diabetes. Although this part of the
W study included only nine patients, each had insulin posi-
e appreciate the response by Rother and tive cells even after their extreme duration of diabetes.
Harlan (1) to our article (2). However, it is AlthoughourfindingsofstimulatedC-peptidemaybean
difficulttounderstandwhattheconfirmatory underestimation of islet secretory capacity as suggested
aspects of the Medalist Study data are with by Rother and Harlan, because of exogenous insulin
respecttothestudiesofLiuetal.(3)andRotheretal.(4), injection before the mixed-meal tolerance test, only 6 of
whichdocumentedminimallevelsofC-peptideproduction the 31 subjects took insulin the morning of the test, and
inindividualswithadiabetesdurationof19.2(cid:1)11.8years that was to bring their fasting blood glucose values to
and21.3(cid:1)10.7years,respectively.Clearly,thisdurationis under250mg/dl,asaferangeforthetesttobeperformed.
significantly lower than the Medalists’ mean duration of We hope these explanations have provided a clear differ-
56.2 (cid:1) 5.8 years. Another difference is the relationship of entiation between our Medalist Study and previous
diseasedurationandresidualC-peptideproduction,which publications.
wasnotsignificantintheMedalistStudybutwasreported
to be significant in the article by Liu et al., with a ACKNOWLEDGMENTS
statistically higher mean duration (P (cid:2) 0.0045) in those No potential conflicts of interest relevant to this article
patients without (26.2 (cid:1) 13.1 years) than those patients were reported.
withresidualC-peptideproduction(19.2(cid:1)11.8years)(3).
One of the most important components of our study is
REFERENCES
the pre- and post mortem data on nine Medalists. Ours is
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sulinpositive(cid:3)-cellmassinanyhumanpopulationoftype 2.KeenanHA,SunJK,LevineJ,DoriaA,AielloLP,EisenbarthG,Bonner-
1diabeticpatientsand,extraordinarily,inindividualswith Weir S, King GL. Residual insulin production and pancreatic (cid:3)-cell
turnover after 50 years of diabetes: Joslin Medalist Study. Diabetes
2010;59:2846–2853
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Massachusetts. not dramatically improved by prolonged immunosuppression and eugly-
Correspondingauthor:GeorgeL.King,[email protected].
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©2010bytheAmericanDiabetesAssociation.Readersmayusethisarticleas
longastheworkisproperlycited,theuseiseducationalandnotforprofit, P,DoschHM,PalmerJP,Brooks-WorrellB,RingM,HarlanDM.Effectsof
and the work is not altered. See http://creativecommons.org/licenses/by exanitidealoneandincombinationwithdaclizumabonbeta-cellfunction
-nc-nd/3.0/fordetails. inlong-standingtype1diabetes.DiabetesCare2009;32:2251–2257
diabetes.diabetesjournals.org DIABETES,VOL.59,DECEMBER2010 e27