Background
Dietary control is one of the cornerstones in the management of diabetes. The high consumption of dates in the Middle East region raises the question about its glycemic index and its effect on the glycemic control of patients with type 2 diabetes.

Aim
This study was designed to determine the glycemic indices of commonly used varieties of dates alone or in mixed meals in healthy subjects compared to patients with type 2 diabetes mellitus. The study aimed to assess the effect of dates on postprandial glucose excursions in individuals with type 2 diabetes mellitus and to determine the time of peak of blood glucose for each type of date using continuous glucose monitoring system (CGMS).

Method
The study included twenty patients with type 2 diabetes of mean age (38.55 ± 7.07 years) who were on therapeutic lifestyle therapy and/or metformin (HbA1c 7-8%) and twenty healthy subjects who were age, sex and body weight matched. Minimed-530g-diabetes-system-with-enlite was used for continuous glucose monitoring. Each meal was consumed within 15 minutes. No drinks were taken one hour before the meal start and two hours afterwards. Composition analysis was carried out for nine date-containing meals alone or mixed. The weights of the flesh of the date meal equivalent to 50 g of available carbohydrates were calculated as shown in table (1). The glycemic indices were determined as ratios of the incremental areas under the response curves for the dates compared to that of glucose. Statistical analysis was done using the Mann-Whitney U test and repeated measures analysis of variance.

 

Type of date	Average weight of each date	Glucose content	Number of dates uses
Rutab	28	5.2	10
Zaghloul	29	5.5	9
Samani	31	4.3	11
Ajwah with butter	18.5	5.6	9
Tamr with milk	22.5	6.5	8
Tamr with coffee	22.5	6.5	8
Ajwah	18.5	5.6	9
Tamr	22.5	6.5	8
Tamr in water	22.5	6.5	8
Glucose	 	 	 
 

Results
There were no statistically significant differences in the GIs between the control and the diabetic groups for the studied meals as shown in table (2)

Glycemic index (Area)	Patients (n= 20)	Control (n= 20)	MW	p
Rutab	27.89 ± 8.34	24.42 ± 7.42	1.136	0.256
Zaghloul	54.24 ± 13.80	50.56 ± 8.57	0.784	0.433
Samani	30.94 ± 9.54	28.89 ± 9.82	0.893	0.372
Ajwah with butter	31.12 ± 6.65	30.12 ± 9.37	0.839	0.402
Tamr with milk	36.31 ± 7.17	34.02 ± 24.77	1.677	0.094
Tamr	31.08 ± 7.36	27.02 ± 16.30	1.001	0.317
Ajwah	29.21 ± 8.59	22.58 ± 18.67	1.407	0.160
Tamr with coffee	37.30 ± 11.15	34.56 ± 18.29	0.893	0.372
Tamr with water	15.71 ± 7.66	13.56 ± 8.21	0.839	0.402
There was a statistically significant difference between both groups according to the time of peak blood glucose; where Tamr with coffee in the diabetic group had the fastest time of peak blood glucose (16.9±1.86) minutes compared to a peak at (126.2±34.217) minutes in the control group. While the addition of butter to Ajwah slowed the time of peak blood glucose (116.4 ± 33.61) minutes in diabetics compared to 177.1±1.94 minutes in the control group.
 

Discussion
These findings point to the value of using CGMS -beyond glycemic index calculation -to study the postprandial glucose excursions and the time of peak blood glucose on consumption of dates among patients with diabetes. The studied types of dates have low glycemic indices when used alone or in mixed meals and did not result in significant postprandial glucose excursions.

Glycemic indices of different varieties of dates in patients with type 2 diabetes and healthy subjects using CGMS