Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-08T11:27:01.997Z Has data issue: false hasContentIssue false
  • English
  • Français

Measuring glycaemic responses: duplicate fasting samples or duplicate measures of one fasting sample?

Published online by Cambridge University Press:  08 March 2007

Thomas M. S. Wolever ,
Blanche Ip  and
Elham Moghaddam
Thomas M. S. Wolever*
Affiliation:
Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada M5S 3E2
Blanche Ip
Affiliation:
Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada M5S 3E2
Elham Moghaddam
Affiliation:
Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada M5S 3E2
*
*Corresponding author: Dr Thomas Wolever, fax +1 416 978 5882, email [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The precision with which glycaemic responses, expressed as incremental area under the curve (AUC), can be measured may be improved by using the average of several measures of fasting blood glucose (FBG). To see if taking two fasting blood samples would increase the precision of AUC, the glycaemic responses elicited by four test meals (50 g glucose; 50 g glucose plus 10 g fat and 10 g protein; 100 g white bread; 100 g white bread plus 10 g fat and 10 g protein) were determined in thirteen overnight-fasted healthy subjects. Two fasting blood samples were taken 5 min apart (−5 min and 0 min before starting to eat) with glucose measured three times in each sample. AUC was calculated using different estimates of FBG derived from the three measures of glucose in the two fasting blood samples and each set of AUC values subjected to ANOVA. Unexpectedly, the results were more precise when AUC was calculated from mean glucose in the 0 min blood sample (FBG0) than from mean glucose in the two different fasting blood samples. The 95 % CI of the AUC calculated using FBG0 in thirteen subjects was ±29·8; to obtain the same CI using the mean of the two fasting blood samples would require fourteen subjects. These results suggest that taking two fasting blood samples does not necessarily improve, and may even reduce, the precision of AUC as a measure of glycaemic response. Further studies are needed before requiring that two fasting blood samples be taken for determining glycaemic index.

Keywords

Human glycaemic responsesCarbohydratesGlucoseGlycaemic indexMethodology
Type
Short Communication
Information
British Journal of Nutrition , Volume 96 , Issue 5 , November 2006 , pp. 799 - 802
Copyright
Copyright © The Nutrition Society 2006

References

Abdallah, L, Chabert, M & Louis-Sylvestre, J (1997) Cephalic phase responses to sweet taste. Am J Clin Nutr 65, 737–743.CrossRefGoogle ScholarPubMed
Augustin, LS, Dal Maso, L, La Vecchia, C, Parpinel, M, Negri, E, Vaccarella, S, Kendall, CW, Jenkins, DJ & Francesch, S (2001) Dietary glycemic index and glycemic load, and breast cancer risk: a case-control study. Ann Oncology 12, 1533–1538.Google Scholar
Benton, D & Nabb, S (2003) Carbohydrate, memory, and mood. Nutr Rev 61, S61–S67.Google Scholar
Brand-Miller, J, Hayne, S, Petocz, P & Colagiuri, S (2003) Low-glycemic index diets in the management of diabetes: a meta-analysis of randomized controlled trials. Diabetes Care 26, 2261–2267.CrossRefGoogle ScholarPubMed
Brouns, F, Bjorck, I, Frayn, KN, Gibbs, AL, Lang, V, Slama, G & Wolever, TMS (2005) Glycaemic index methodology. Nutr Res Rev 18, 145–171.CrossRefGoogle ScholarPubMed
Coutinho, M, Gerstein, HC, Wang, Y & Yusuf, S (1999) The relationship between glucose and incident cardiovascular events. A metaregression analysis of published data from 20 studies of 95,783 individuals followed for 12.4 years. Diabetes Care 22, 233–240.Google Scholar
Ebbeling, CB, Leidig, MM, Sinclair, KB, Hangen, JP & Ludwig, DS (2003) A reduced-glycemic load diet in the treatment of adolescent obesity. Arch Ped Adolesc Med 157, 773–779.CrossRefGoogle ScholarPubMed
Frost, G, Leeds, A, Trew, G, Margara, R & Dornhorst, A (1998) Insulin sensitivity in women at risk of coronary heart disease and the effect of a low glycemic diet. Metabolism 47, 1245–1251.CrossRefGoogle ScholarPubMed
Higginbotham, S, Zhang, Z-F, Lee, I-M, Cook, NR, Giovannucci, E, Buring, JE & Liu, S (2004) Dietary glycemic load and risk of colorectal cancer in the Women's Health Study. J Natl Cancer Inst 96, 229–233.Google Scholar
Kringle, RO & Johnson, GF (1986) Statistical procedures. In Textbook of Clinical Chemistry, pp. 287–355 [Tietz, NW, editor]. Philadelphia: WB Saunders Co.Google Scholar
Liu, S, Willett, WC, Stampfer, MJ, Hu, FB, Franz, M, Sampson, L, Hennekens, CH & Manson, JE (2000) A prospective study of dietary glycemic load, carbohydrate intake and risk of coronary heart disease in US women. Am J Clin Nutr 71, 1455–1461.Google Scholar
Melanson, KJ, Westerterp, MS, Smith, FJ, Campfield, LA & Saris, WHM (1999) Blood glucose patterns and appetite in time-blinded humans: carbohydrate versus fat. Am J Physiol 46, R337–R345.Google Scholar
Salmerón, J, Manson, JE, Stampfer, MJ, Colditz, GA, Wing, AL & Willett, WC (1997) Dietary fiber, glycemic load and risk of non-insulin-dependent diabetes mellitus in women. J Am Med Assoc 277, 472–477.Google Scholar
Standards Australia (2005) DR 05435 Glycemic index of foods (Draft for Public Comment). Accessed 5 December 2005. www.standards.com.au/catalogue/script/Details.asp?DocN=MSWD05435ATCRDGoogle Scholar
Wolever, TMS (2004) Effect of blood sampling schedule and method of calculating the area under the curve on validity and precision of glycaemic index values. Br J Nutr 91, 295–301.CrossRefGoogle ScholarPubMed
Wolever, TMS, Jenkins, DJA, Jenkins, AL & Josse, RG (1991) The glycemic index: methodology and clinical implications. Am J Clin Nutr 54, 846–854.Google Scholar
Wolever, TMS & Mehling, C (2002) High-carbohydrate/low-glycaemic index dietary advice improves glucose disposition index in subjects with impaired glucose tolerance. Br J Nutr 87, 477–487.CrossRefGoogle ScholarPubMed
Wolever, TMS, Vorster, HH & Björk, I (2003) Determination of the glycaemic index of foods: interlaboratory study. Eur J Clin Nutr 57, 475–482.Google Scholar