Diet Liberalization and Metabolic Control in Type I ... - Diabetes Care

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iet Liberalization and Metabolic Control in Type I Diabetic Outpatients Treated by Continuous Subcutaneous Insulin Infusion

E. CHANTELAU, G. E. SONNENBERG, I. STANITZEK-SCHMIDT, F. BEST, H. ALTENAHR, AND M. BERGER

In 10 type I diabetic outpatients treated by continuous subcutaneous insulin infusion (CSII), dietary habits and metabolic control were investigated. Under conditions of a conventional diabetes diet (including 5-6 meals per day and a strictly planned meal intake) as well as under a "less restricted diabetes diet" (e.g., free choice of number, timing, and amount of carbohydrate intake) near normoglycemia could be achieved. Mean daily blood glucose levels did not change significantly when the patients' nutrition was alternated between both diets. During the "less restricted diabetes diet," the patients opted for a rather high fat intake (51 ± 5% fat, 34 ± 5% carbohydrate, and 15 ± 2% protein). Despite this unintended dietary behavior, serum lipids and body weight remained normal after an observation period of 4 - 6 mo. It is concluded that during permanent near normoglycemia achieved by CSII a partial liberalization of the diabetes diet does not introduce any short-term or long-term metabolic risk factors for cardiovascular diseases, DIABETES CARE 5.- 612-616, NOVEMBER-DECEMBER 1982.

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education, they represented a group of highly motivated and well-trained diabetic patients. CSH treatment. CSII therapy was installed during a 4 - 5 day hospitalization during which the patients got a special diabetes education concerning pump-handling, diet, and blood glucose monitoring. CSII was performed as described elsewhere (cf. 5). The basal insulin infusion rates were adjusted individually during the hospital stay to achieve basal near normoglycemia. The patients were taught to give their prandial insulin boluses 15 min before each meal; the amount of insulin applied preprandially was to be assessed according to the amount of carbohydrates ingested and the preprandial glycemia. Hypoglycemia should be avoided and postprandial blood glucose should not exceed 160 mg/dl. Diet recommendations. Diabetes diet was recommended according to the standards of the American Diabetes Association;6 e.g., meal planning, including 5—6 meals per day METHODS (main meals and snacks), was instructed as well as food exPatients. Ten patients with type I diabetes mellitus were stud- changing. Fifty percent of the total caloric intake should be ied after obtaining their informed consent. Their clinical derived from carbohydrates (CHO), so simple sugars were to data are listed in Table 1. The basal C-peptide levels were be avoided. Estimation of the CHO content of common below 0.2 ng/ml. There was no evidence for hyperlipopro- foodstuffs was educated: in a special test, the patients were teinemia when the insulin therapy was changed from subcu- able to assess the CHO content of 18 common foodstuffs, extaneous injections to CSII. All patients had opted voluntar- pressed in bread-exchange units (1 BE = 12 g CHO, West ily for the CSII treatment; regarding their diabetes German exchange system).

he introduction of continuous subcutaneous insulin infusion (CSII) into the therapy of type I diabetes mellitus has opened the possibility to achieve near normoglycemia at acceptable costs and risks for a great number of type I diabetic patients.1 In addition, this kind of treatment is subjectively acceptable and even appreciated at least by selected groups of patients.2 Since its introduction, CSII treatment has always been carried out using a conventional diabetes diet regimen (cf. 3). Preliminary observations indicated, however, that CSII treatment might allow to partially lift dietary restrictions without losing optimal blood glucose control.4 This study was performed to evaluate the effects of a limited liberalization of diabetes diet on blood glucose control and serum lipid levels in type I diabetic patients under conditions of CSII.

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DIABETES CARE, VOL. 5 NO. 6, NOVEMBER-DECEMBER 1982

DIET LIBERALIZATION AND METABOLIC CONTROL WITH CSII/E. CHANTELAU AND ASSOCIATES

TABLE 1 Clinical data of the patients before (A) and 4 - 6 mo after the installation of CSII and relatively unrestricted diabetes diet (B)

Body wt (Broca index) Patient

Age (yr)

26 34

1

2 3 4 5 6 7 8 9 10 mean

±SD

29 19 18 31 26 18 28 31 26 ±6

Sex

Occupation

M

Nursing orderly Teacher Secretary Nursing orderly Student House painter Student Student Housewife Secretary

W W

M M M M

M W

W

Duration of diabetes (yr)

16 24 18 13

7 11 22 9 6 10 14 ±6

A

B

0.93 0.89 0.95 0.89 0.74 0.84 0.83 0.79 0.87 0.91 0.86 ±0.06

0.93 0.94 0.95 0.89 0.84 0.84 0.83 0.86 0.87 0.92 0.89 ±0.05 NS

HbA

(% of total Hb) A

B

8.7

7.9 7.2 6.6 7.6 7.4 7.0

9.1 9.2

10.0 8.7 12.6 7.8 8.9 8.1

13.6

7.2 7.8 6.7 7.8

9.7 7.3 ±1.9 ±0.5 P < 0.0025

Total cholesterol (mg/dl) A

B

199 239 199 214 179 189 179 164 194 199 196 ±21

209 239 269 179 194 185 139 159 224 239 204 ±40 NS

Triglycerides (mg/dl) A

B 58 81 160 119 — 63 111 145

86 82

67 148 99 101 86 56 66 83

74 101 102 ±37

87 ±26 NS

HDLcholesterol (mg/dl) A

B

42

60

50

72 76 49 46 40 35

37 28 39 62 32 55 38 85

81

52 82 59 ±17

47 ±17 P < 0.05

Broca index calculated as body weight/height (cm) — 100.

Blood glucose self-monitoring. Blood glucose self-monitoring

was performed under outpatient conditions daily before and after meals. CHO intake, insulin dosages, and blood glucose measurements were recorded daily. Materials. CSII treatment was performed using the Mill Hill Infuser HM 1001 (Muirhead, England). Regular insulin (Actrapid) was infused via butterfly cannula into the anterior abdominal wall. Blood glucose measurements were performed from capillary blood, using a battery-driven reflectometer (Glucosemeter, Wolf, FRG). At onset and at the end of the study period, HbA lc , total cholesterol, HDL-cholesterol, and triglycerides were determined using methods described elsewhere.7'8 The normal range of HbA lc in our laboratory is 4.5-7.8% of total hemoglobin. Statistical methods. All measurements given in the text, figures and tables are expressed as means ± SD. For the calculation of statistically significant differences, Student's t test was used for paired and unpaired data. EXPERIMENTAL PROCEDURES

Following the discharge from our metabolic ward, the patients were seen once a week or biweekly in our diabetes clinic. At the earliest, 4 - 5 wk after the initiation of CSII, the study was started. The protocol of the study consisted of three parts. Part I. To compare a conventional diabetes diet to a diabetes diet liberalized within certain limits, six of the patients (nos. 1, 2, 3, 4, 5, and 6) were asked to record blood glucose self-monitoring, CHO intake and insulin dosages during 2 - 3 days strictly adhering to a conventional diabetes diet (5-6 meals per day, planned timing and distribution of CHO intake). Thereafter, they were allowed to partially lift dietary restrictions and have a "less restricted diabetes diet" (free

choice of number, timing, and CHO content of meals) for at least another 2 days. CHO intake, blood glucose self-monitoring, and insulin dosages were recorded as initial. Simple sugars as well as rapidly absorbed carbohydrates, such as fruit juices, were to be avoided with both diets. No logs were kept as to the intake of fat and protein. Thereafter, all patients participating in the study were allowed to choose between the conventional diabetes diet and the "less restricted diabetes diet": all of them opted for the "less restricted diabetes diet." Part 2. To evaluate dietary habits and blood glucose control under conditions of ambulatory CSII therapy and "less restricted diabetes diet," seven patients (nos. 1,3,5, 7, 8, 9, and 10) were visited at home or at their working places on 3 consecutive days. Food intake (quantities assessed) and insulin dosages were recorded and blood glucose measurements were preformed exactly 15 min before and 60 min after each main meal by one of us. Part 3. After 4 - 5 mo of CSII therapy and "less restricted diabetes diet," all 10 patients were re-examined including the determination of body weight, HbA l c , and serum levels of total cholesterol, HDL-cholesterol, and triglycerides. RESULTS

Comparison of conventional diabetes diet and "less restricted dia-

betes diet." With conventional diabetes diet, the patients had 5-6 meals per day with a total CHO intake of 183 ± 60 g/day. The timing of the meals was kept strictly constant and the CHO intake at the main meals was virtually identical (Table 2). With the "less restricted diabetes diet," the patients had only 3 - 4 meals per day with a total CHO intake of 149 ± 50 g/day. Meal times varied from day to day; breakfast was postponed by up to 94 ± 55 min from one day to the other, lunchtime varied by about 48 ± 43 min and supper-


613


TABLE 2 Actual differences between conventional diabetes diet (CDD) and the "less restricted diabetes diet" (LRDD) during 16 patient days each

CDD Meal planning Number of meals per day Postponing of meals (min)

CHO intake (g per day) Percent of total caloric intake CHO intake (g per meal) Breakfast Lunch Supper Snacks (each)

LRDD

yes

no

5-6 no

3-4

183 ± 60

149 ± 50

approximately 42% 39 42 42 26

± ± ± ±

94 ±:55 48 ±:43 83 ±: 90

breakfast lunch supper

11 12 16 16

34 ± 5% 40 51 53 12

± ± ± ±

12 21 24 36

Data obtained from six type 1 diabetic patients on CSII during 2 - 3 days on each of the diets.

time by about 83 ± 90 min, respectively. The CHO intake at the main meals varied from 40 ± 12 g CHO at breakfast to 53 ± 24 g CHO at supper (Table 2). The analysis of a total of 197 blood glucose measurements performed by the patients themselves (range 4-10 measurements per day) revealed no significant difference in glycemia between the conventional diabetes diet and the "less restricted diabetes diet." In fact, the blood glucose profiles were virtually identical (Figure 1). The mean of all blood glucose values on the conventional diabetes diet (N = 16 patient days) was 105 ± 28 mg/dl compared with 96 ± 25 mg/dl on the "less restricted diabetes diet" (N = 16 patient days; NS). Evaluation of dietary habits and blood glucose control under conditions of the "less restricted diabetes diet." During the ob-

servation period of 21 patient days, the patients had a total CHO intake of 156 ± 46 g/day. The total caloric intake ranged from 1300 kcal/day (26 kcal/kg body wt • day) to 3800 kcal/day (43 kcal/kg body wt • day), depending on the different intensities of physical work occupying the patients. The food consumed was rather rich in fat (51 ± 5% of the total caloric intake derived from fat, 34 ± 5% from CHO, and 15 ± 2% from protein). The mean blood glucose, calculated from 126 measurements taken exactly 15 min before and 60 min after each main meal was 105 ± 26 mg/dl; the mean blood glucose 60 min after the main meals did not exceed 140 mg/dl (Figure 2). During the observation period, two mild hypoglycemic reactions occurred which were due to unexpected physical activity. The records of the prandial insulin requirements for one bread-exchange unit (1BE = 12 g CHO) showed that a higher insulin supply was needed for breakfast (1.6 ± 0.6 U/BE) than for lunch (1.1 ± 0 . 3 U/BE) and for supper (1.2 ± 0.3 U/BE), but the differences were statistically insignificant. The basal insulin infusion rate was 26 ± 5 U/day. The long-term follow-up after 4—6 mo of CSII and the "less restricted diabetes diet" demonstrated normal levels of HbA lc and serum lipids (with an increase of HDL-cholesterol from 47 ± 17 mg/dl to 59 ± 17 mg/dl; P < 0.05); the body weight was maintained within the normal range (Table 1). DISCUSSION

Fixation of timing and carbohydrate content of 5—6 meals per day is a primary compliance problem with the conventional diabetes diet in patients whose treatment includes the use of long-acting insulin preparations.9 The adherence to such a rigid dietary formula represents a serious impairment

BLOODGLUCOSE ( m g / d l ) 16o i

12o „

8o .

4o -

1^

,oo

.00

11oo

13oo

15oo

17oo

19oo

21oo

2 3°° 2 4°° TIME

FIG. 1. Blood glucose profiles in six type I diabetic patients on CSll during 16 patient days on a conventional diabetes diet ( • 16 patient days on a "less restricted diabetes diet" ( O O ) ; means ±SD.

614


• ) and during


BLOODGLUCOSE (mg/dl) 16o -.

12o

-O 80 -

4o -

I -15 min.

SUPPER

LUNCH

BREAKFAST

I +60 min.

I -15 min

+60 min.

I -15 min.

I +60 min.

FIG. 2. Blood glucose levels £>re- and postprandial in seven fjpe I diabetic patients on CSll and "less restricted diabetes diet" (N = 21 patient days; mean ±SD). of the quality of life for most of the patients. In fact, the necessity to eat at scheduled times—even when one is not hungry at all—seems to be a more awkward burden to the majority of type 1 diabetic patients than the restriction in the use of foods containing simple sugars. Therefore, adherence rates to the conventional diabetes diet are rather poor in insulin-dependent diabetic patients.9'10 The introduction of CSII therapy (using regular insulin only) with its distinct differentiation between a basal insulin supply and various prandial extra boluses of insulin offered the possibility to liberalize the conventional meal planning. Clinical observations, primarily made by the patients themselves, indicated that with properly adjusted basal insulin infusion rate, snacks and even main meals could easily be advanced, postponed, or even omitted without deterioration of optimal blood glucose control.4 In this study, we have proven that during CSII in well-educated, normal weight type I diabetic patients without primary hyperlipoproteinemia a certain liberalization of the diabetes diet under strictly supervised circumstances has no untoward effects on glycemic control when compared with the conventional diabetes diet. In spite of skipping or postponing meals, near normoglycemia was maintained throughout the whole period of the study. Mean blood glucose levels even after main meals at the "less restricted diabetes diet" did not exceed 140 mg/dl, suggesting that the delivery of the prandial insulin boluses by the patients was adequate. There was no advantage of the conventional diabetes diet compared with the "less restricted diabetes diet" during an observation period of 16 days each with regard to the levels of glycemia throughout the day (Figure 1). It was, however, of concern to us that with the "less restricted diabetes diet," the patients decided to lower the

CHO intake quite considerably below the standards recommended by our dietitian; similar dietary habits have been observed by Hjermann and co-workers in healthy men.11 This unintended nutritional habit resulted in a high fat intake, which has been suggested to be a risk factor for cardiovascular diseases. Therefore, we measured the known metabolic cardiovascular risk factors in a long-term follow-up of these patients on CSII and the "less restricted diabetes diet": even 4 - 6 mo following the liberalization of the diet, all patients had maintained normal HbA lc levels (indicating permanent near normoglycemia), normal serum lipid levels, and normal body weight (Table 1). These results are similar to the observations of Sosenko and co-workers, who demonstrated that in diabetic patients a normalization of blood glucose control is associated with normalized serum lipid levels.12 The "less restricted diabetes diet" used in our study, e.g., free choice of number, timing, and CHO content of meals, is in no way equal to a so-called "free diet"; quite in contrast the patients still have to follow certain dietary rules. Like all diabetic patients, those on CSII have to avoid simple sugars, but more than that they have to carefully assess the CHO content of any food they are going to eat in order to apply an appropriate pre-meal insulin bolus. They have to work out their individual appropriate pre-meal insulin bolus for different kinds of CHO-containing foods as well as for various situations (for example, under conditions of physical activity and the time thereafter and during intercurrent illness) and in relation to the time of the day. They have to avoid excessive amounts of CHO and to keep in mind the size of the preceding meal and the insulin bolus delivered accordingly, because the bigger the bolus, the longer the serum insulin elevation lasts.13-14 These particular aspects require a strict adherence to blood


615


glucose self-monitoring and frequent recording of the results in order to draw prospective conclusions. The patients have to work out all this by themselves, because the subcutaneous insulin requirements of a diabetic individual cannot be predicted precisely.15 Thus, a high degree of education and cooperation is needed on the part of the patients. Nevertheless, the relative freedom to adapt eating habits partially to those of nondiabetic people offers a considerable gain for the quality of life to these patients. Pending further long-term studies, these data suggest that type I diabetic patients on CSII can maintain near normoglycemia even on a relatively unrestricted diabetes diet, provided they are able to adjust their insulin infusion rates appropriately. Despite the liberalization of frequency, timing, and CHO content of meals, resulting in a primarily unintended drop of the daily CHO consumption and an increased fat intake, there was no indication for the development of metabolic cardiovascular risk factors in this selected group of type I diabetic patients on CSII. Thus, it might be feasible under these circumstances (permanent near normoglycemia in well-educated type I diabetic patients on CSII) to improve the quality of life by a partial liberalization of the rigid restrictions associated with the conventional diabetes diet without introducing any short-term or long-term metabolic risk. ACKNOWLEDGMENTS: This work was supported in part by the Wissenschafts-minister des Landes Nordrhein-Westfalen (grant to Dr. Sonnenberg). The cooperation of Gaby Gosseringer, R.D. and the technical assistance of Christiane Broermann are gratefully acknowledged.

From Medical Department E, Diisseldorf University, Moorenstrasse 5, D-4000 Diisseldorf, West Germany. Address reprint requests to Michael Berger at the above address. REFERENCES 1

Anonymous: New insulin-delivery systems for diabetics. Lancet 1: 1275-77, 1979. 2 Sonnenberg, G. E., Kurz, P., Chantelau, E., and Berger, M.: Psychological and somatic acceptance of continuous subcutaneous insulin infusion (CSII) treatment by type I diabetic patients. Pro-

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ceedings of the International Symposium on artificial systems for insulin delivery. Massi-Benedetti, M., Ed. New York, Raven Press, 1981. In press. 3 Dunn, F. L., Pietri, A., and Raskin, P.: Plasma lipid and lipoprotein levels with continuous subcutaneous insulin infusion in type I diabetes mellitus. Ann. Intern. Med. 95: 426-31, 1981. 4 Chantelau, E., Sonnenberg, G. E., Altenahr, H., and Berger, M.: Continuous subcutaneous insulin infusion (CSII) allows a partial lift of dietary restrictions in type I diabetic patients. Diabetologia 21: 258, 1981. Abstract. 5 Pickup, J. C , Viberti, G. C , Bilous, R. W., Keen, H., Alberti, K. G. M. M., Home, P. D., and Binder, C : Safety of continuous subcutaneous insulin infusion: metabolic deterioration and glycaemic autoregulation after deliberate cessation of infusion. Diabetologia 22: 175-79, 1982. 6 American Diabetes Association: Principles of nutrition and dietary recommendations for individuals with diabetes mellitus. Diabetes 28: 1027-30, 1979. 7 Berchtold, P., Berger, M., Jorgens, V., Daweke, C , Chantelau, E., Gries, F. A., andZimmermann, H.: Cardiovascular risk factors and HDL-cholesterol levels in obesity. Int. J. Obes. 5: 1-10, 1981. 8 Fliickiger, R., and Winterhalter, K. H.: In vitro synthesis of hemoglobin A, c . FEBS Lett. 71: 356-63, 1976. 9 Mann, J. I.: Diet and diabetes. Diabetologia 18: 89-95, 1980. 10 Mehnert, H.: Zur diatetischen Behandlung des Diabetes mellitus. Dtsch. Med. Wochenschr. 86: 1469-73, 1961. 11 Hjerman, I., Velve Byre, K., Holme, I., and Leren, P.: Effect of diet and smoking on the incidence of coronary heart disease. Lancet 2: 1303-10, 1981. 12 Sosenko, M. M., Breslow, J., Miettinen, O. S., and Gabbay, K. H.: Hyperglycemia and plasma lipid levels: covariations in insulin-dependent diabetes. Diabetes Care 5: 40-43, 1982. 13 Service, F. J., Westland, R. E., Hall, L. D., Clemens, A. H., and Rizza, R. A.: Effects of meal size, time of day and sequence of meal ingestion on insulin requirements for prandial glucose control in insulin-dependent diabetic subjects. Diabetes 30(Suppl. 1): 154, 1980. Abstract. 14 Schlichtkrull, J.: The absorption of insulin. Acta Paediatr. Scand. (Suppl.): 97-102, 1977. 15 Chantelau, E., Sonnenberg, G. E., Altenahr, H., Berger, M., and Heding, L. G.: Basal insulin infusion rates, free IRI and fasting blood glucose in type I diabetic patients on continuous subcutaneous insulin infusion. Eur. J. Clin. Invest. 12 (Suppl. 1): 6, 1982. Abstract.
