Research Article - Journal of Diabetology (2017) Volume 1, Issue 1

Daily carbohydrate intake correlates with HbA1c in low carbohydrate diet (LCD).

Koji Ebe^1,2*, Hiroshi Bando^2,3, Kokoro Yamamoto^1,2, Masahiro Bando⁴, Yoshikazu Yoneio⁵

¹Takao Hospital, Kyoto, Japan

²Low Carbohydrate Diet Promotion Association, Kyoto, Japan

³Tokushima University / Medical Research, Tokushima, Japan

⁴Department of Nutrition and Metabolism, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan

⁵Anti-Aging Medical Research Center, Graduate School of Life and Medical Sciences, Doshisha University, Kyoto, Japan

*Corresponding Author:

Hiroshi Band
Tokushima University /Medical Research Nakashowa 1-61
Tokushima 770-0943 Japan
Tel: +81-90-3187-2485
E-mail: pianomed@bronze.ocn.ne.jp

Accepted date: November 24, 2017

Abstract

Background: There is an ongoing discussion about Low Carbohydrate Diet (LCD) and Calorie Restriction (CR). Authors and colleagues have initiated LCD in Japan, and reported clinical research studies on LCD and related biomarkers. Subjects and Methods: Subjects were 51 patients with Type 2 diabetes mellitus (T2DM) with a mean age of 62.4 ± 6.9 years old. Patients were admitted for 14 days for treatment of super LCD formula, including 12% carbohydrates, 64% lipids, 24% protein with 1400 kcal/day. Six months later, the detail of meals for 7 days, HbA1c and lifestyle items were investigated. Results: Subjects were classified into 2 groups according to the level of HbA1c at 7%. HbA1c was 6.1% vs 7.4%, and carbohydrate intake a day was 55.2g vs 123.6 g in group 1 and 2, respectively. Group 1 tended to have more usage of food and spice for LCD. There was significant correlation between HbA1c and carbohydrate intake (p<0.01). Discussion and Conclusion: We adopted super LCD formula meal in this current study, including 12% of carbohydrate ratio. As to American Diabetes Association (ADA), carbohydrate intake per day in LCD would be less than 130g or less than 26% total energy per day. From our data, mild LCD might not be enough to maintain HbA1c less than 7%. Current results would be the fundamental data for LCD treatment for T2DM in the future.

Keywords

CR: Calorie Restriction, LCD: low carbohydrate diet, M value: Morbus value, CGM: continuous glucose monitoring

Abbreviations

CR: Calorie Restriction, LCD: Low-Carbohydrate Diet, T2DM: Type 2 Diabetes Mellitus M value: Morbus value, MAGE: mean amplitude of glycemic excursions, VLCKD: Very low-carbohydrate ketogenic diet, CGM: continuous glucose monitoring

Introduction

Various discussion has been continued concerning Low Carbohydrate Diet (LCD) and Calorie Restriction (CR) for decades [1-3]. Several clinical efficacy of LCD have been gradually known and more prevalent. In western countries, Bernstein and Atkins have originally started to introduce LCD [4-7].

On the other hand, authors and colleagues have initiated LCD in Japan, and reported thousands of cases with clinical efficacy [8,9]. Moreover, we have investigated related research concerning Morbus (M) value, lipid metabolism, renal function and ketone bodies [10-12]. We have also proposed 3 types of LCD formula meals, which are super LCD, standard LCD and petit LCD. As our continuous investigation, we would clarify the influence of carbohydrate intake to HbA1c level. In this study, we investigate actual daily intake of carbohydrate amount and the influence for HbA1c level.

Subjects and Methods

Subjects in this study were 51 patients (M/F 30/21) with T2DM, who are 62.4 ± 6.9 years old (mean ± SD).

Methods included 3 stages as follows:

1) Patients with T2DM were admitted for 14 days for further evaluation and treatment of T2DM. The formular meal were as follows: 0n day 1 and 2, CR diet was provided, including 60% carbohydrates, 25% lipids and 15% protein with 1400 kcal/day. On day 3-14, LCD was provided, including 12% carbohydrates, 64% lipids and 24% protein with 1400 kcal/day. The strict LCD has been called “super-LCD formula” in our clinical research for LCD. It is one of the Very low-carbohydrate ketogenic diet (VLCKD) by the definitions of LCD [6,11-13]. Comparison of the meal between CR and LCD is shown in Figure 1.

Figure 1: Typical diabetic meals (CR and LCD).
a. Calorie restriction with 480 kcal with carbohydrate 60%
b. Low Carbohydrate Diet (Super-LCD) with 480 kcal with carbohydrate 12%.

As for anti-diabetic medications, subjects had no medicine during 14 days, in order to evaluate LCD therapy in strict way.

2) After discharge from the hospital, they have regular visit in every 4 weeks on out-clinic. Six months later, we investigated the detail of meals for 7 days. The questionnaire included actual intake of meals, medicine, lifestyle, snacks, with some pictures of meals when needed. Authors and registered dieticians analyzed the carbohydrate amount by using the computer. According to HbA1c level, subjects were classified into two groups: group 1 is <7% and 7% or greater. We have checked meal habit and the correlations between HbA1c and average carbohydrate intake per day.

3) Apart from the studies above, 2 cases were investigated in details out of 51 subjects. Case 1 is 70 year-old female, with M value calculated by daily profile of blood glucose 7 times a day. Case 2 is 70 year-old men, with daily profile of blood glucose all day for 7 days, using Continuous Glucose Monitoring (CGM) device.

Glucose profile and M value

During admission, daily profile of blood glucose was studied a day, which are 8, 10, 12, 14, 17, 19, 22h. It was measured on day 2 for CR and day 4 for LCD. According to the glucose profile, Morbus (M) value was calculated.

For years, M value has been a useful index showing blood sugar level and also mean amplitude of glycemic excursions (MAGE) [14-17]. As to the glucose variability, we measured daily profiles of blood glucose 7 times a day, and calculated average glucose level and M value. M value has been introduced and used for evaluating MAGE. M value is represented and calculated as a logarithmic transformation of the deviation of glycemia from an arbitrary assigned “ideal” glucose value. It expresses both the mean glucose value and the effect of glucose swings [14-18].

[M value can be calculated by the following formula: M=MBS + MW, where MW=(maximum blood glucose − minimum glucose)/20; M S=the mean of MBSBS; MBSBS=individual M-value for each blood glucose value calculated as (absolute value of [10 × log (blood glucose value/120)])3.

M value has been evaluated as follows: below 180 is normal and standard, 180-320 is borderline, and more than 320 is abnormal. There have been arguments about the adequate sampling times a day, with the precise evaluation of glucose variability and MAGE. The results on 7 times or 20 times a day were similar [14-17,19]. It showed the similar results in compared to the continuous glucose monitoring (CGM) [18,19,20].

Statistical Analyses

On this study, data were showed as the mean +/- standard deviation (SD) and represented as median, quartile of 25% and 75% in biomarkers. When we investigate statistical analyses, correlation coefficients were calculated by using Pearson or Spearman test of the Microsoft Excel analytical tool [21].

[Comparisons between the groups were made using the Wilcoxon rank sum test or the. Bonferroni multiple comparison (Lambert method). We considered statistically significant, when the significance level was less than 5%.

Ethical considerations

We proceeded this study in compliance with the ethical principles. They are the Declaration of Helsinki and also Japan's Act on the Protection of Personal Information along with the Ministerial Ordinance on Good Clinical Practice (GCP) for Drug. The latter was from the Ordinance of Ministry of Health and Welfare No. 28 of March 27, 1997). We have no ethical committee meeting related to this research, and obtained informed consent from the subjects.

Results

1. HbA1c values

Subjects were classified into 2 groups according to the level of HbA1c at 7%. Average HbA1c was 6.1% and 7.4%, respectively (Table 1). Average carbohydrate intake in each group was 55.2g and 123.6 g, respectively.

Table 1. HbA1c and carbohydrate intake of the subjects.

2. Meal habit

Both groups showed similar ratio of snack habits. The ratio of practical use of food and spice for LCD in daily life were higher in group 1 compared with group (Table 2).

Table 2. Comparison of diet habits in 2 groups.

3. Carbohydrate intake per day

There was significant correlation between HbA1c and carbohydrate intake per day (p 0.01), shown in Figure 2. The regression curve showed y=42.547x - 200.9 with R²=0.4838.

Figure 2: Correlation between HbA1c and Carbohydrate intake per day. There are significant correlation between HbA1c and carbohydrate intake per day (p<0.01). According to the value of HbA1c, subjects were classified into group 1 (HbA1c<7.0%) and group 2 (HbA1c > 7.0%). Blue round plots represent group 1, and red square plots represent group 2.

4. Morbus value

Case 1 was 70 year-old female with HbA1c 8.9% on admission, who has 156 cm in height, 49kg in weight, 20.1 in body mass index (BMI) with no medication for T2DM. Changing from CR to LCD, daily profile of blood glucose and M value showed remarkable decrease in only 2 days (Figure 3).

Figure 3: Case 1 with M value investigation. Case 1 was 70 year-old female with HbA1c 8.9%, who has 156 cm in height, 49 kg in weight, 20.1 in body mass index (BMI) with no medication for T2DM. As the meal changed from CR to LCD, blood glucose and M value decreased remarkably in only 2 days.

5. Continuous glucose monitoring (CGM)

Case 2 was 70 year-old male with HbA1c 7.1%, who has 162 cm in height, 54 kg in weight, 20.6 in BMI with no medication for T2DM. He had super-LCD on Day 1,2,3,5,6,7, and formular CR diet on Day 4. Blood glucose profile due to continuous glucose monitoring (CGM) was shown in Figure 4, indicating that carbohydrate loading caused remarkable increase of daily profile of blood glucose.

Figure 4: Case 2 with continuous glucose monitoring (CGM) investigation. Case 2 was 70 year-old male with HbA1c 7.1%, who has 162 cm in height, 54 kg in weight, 20.6 in BMI with no medication for T2DM. He had super-LCD on Day 1,2,3,5,6,7, and formular CR diet on Day 4. (LCD; low carbohydrate diet, CR; calorie restriction)

Discussion

As for the development of LCD worldwide, Atkins, Bernstein and other researchers have contributed much in Western countries [1-7]. In Japan, Authors and colleagues have investigated and developed LCD in comparison with CR for years with clinical research studies [8-13], We have also developed social movement, continuing the activity of Japan LCD Promotion Association with lectures and journals.

The content of CR diet was made according to the guideline of Japan Diabetes Society, in which PFC ratio is 14.7%, 26.9%, 58.4%, respectively [22]. This ratio has been almost the same from 1985 to 2015 on the national survey in Japan [23]. In general, PFC ratio has been 15:25:60.

On contrast, we proposed three patterns of LCD, which are super-LCD, standard- LCD and petit LCD. The carbohydrate ratio of these 3 types are, 12%, 26% and 40%, respectively. Our simple advice would be as follows: 1) super: avoid carbohydrate in 3 meals for super LCD, 2) standard: avoid carbohydrate in 2 meals, 3) petit: avoid carbohydrate in only supper. These are easily understood and continued for everyone.

Current study revealed two important results as follows: 1) there was a significant difference of carbohydrate intake in 2 groups, which are 55 g vs. 124 g per day, and 2) subjects in group 1 usually pay attention to using foods and spices connected to LCDs.

As for the recommendation from American Diabetes Association (ADA), carbohydrate intake per day would be less than 130 g or less than 26% total energy per day [6,24]. However, taking our results into consideration, this is not enough to maintain HbA1c less than 7%.

Meal habits are different in Western and Asian countries. In the latter, they usually have overconsumption of starch foods such as rice and crops, inducing a sharp and rapid postprandial hyperglycemia [25-27]. By this glucose response, an insulin surge would contribute to the etiology of diabetes [28].

Effect of co-ingestion of amino acids with rice on glycemic response was recently studied, and rice and amino acid mixture revealed the best results in decreasing the peak blood level [29]. By usage of this way, Asian people can reduce postprandial hyperglycemia due to carbohydrate-rich rice meals [30-32].

The effect of Japanese rice bowl topped with beef to blood glucose was investigated. It includes protein 18.4 g, fat 20.9 g and carbohydrate 82.9 g [33]. After it was given to 12 volunteers of 26 years old in average, blood glucose was increased 65 mg/dL in 30 min. Consequently, even if the subjects are young and healthy, blood glucose showed remarkable increase by intake of rice.

In association with report above [33], one of the limitation of this study would be the subjects including only Japanese with the characteristic meal habit taking considerable carbohydrate such as rice and noodle.

There has been a large-scale epidemiological study, “The Prospective Urban Rural Epidemiology (PURE) study”. It included 140 thousands subjects in 600 communities from 17-18 countries around the world [34,35]. By studying fats and carbohydrate intake, higher carbohydrate intake with an increased risk of total mortality (HR 1.28) were observed. Then, lower intake of carbohydrate would be recommended [36,37].

Recently, International Diabetes Federation (IDF) showed the problems worldwide [38], in which diabetes, obesity and metabolic syndrome (Met-S) have been increasing, and diabetic prevalence will be increasing from 8.8% in 2015 to 10.4% in 2040 [39,40]. IDF summarized Standards of Medical Care in Diabetes in 2015 [41]. In this guideline, monitoring carbohydrate intake, carbohydrate counting and experiencebased estimation would be crucial. Continuous investigation of eating patterns and macronutrient distribution would lead to achieving glycemic control in the future.

Conclusion

Significant correlation between HbA1c and carbohydrate intake per day was shown, indicating the efficacy of LCD.

Furthermore, mild LCD about less than 130 g of carbohydrate per day seemed not be enough to maintain HbA1c less than 7%. Current results would become the fundamental data for LCD treatment for T2DM in the future.

Acknowledgements

As to current study, some part of the content was presented at the 89^th and 90^th Scientific Meeting of Japan Endocrine Society (JES) Annual Congress, Kyoto, 2016 and 2017.

The authors would like to appreciate subjects and people related to this research for their understanding, cooperation and support.

Conflicts of Interest

The authors have no conflicts of interest.

References

1. Atkins R. Dr. Atkins’ new diet revolution, Rev edn. Avon books, New York, 1998.
2. Bernstein RK. Dr. Bernstein’s Diabetes solution: The Complete Guide to Achieving Normal Blood Sugars. Little, Brown US, New York, 2007.
3. Shai I, Schwarzfuchs D, Henkin Y, et al. Weight loss with a low-carbohydrate, mediterranean, or low-fat diet. N Engl J Med 2008;359:229-41.
4. Schwarzfuchs D, Golan R, Shai I, et al. Four-year follow-up after two-year dietary interventions. N Engl J Med 2012;367:1373-74.
5. Atallah R, Filion KB, Wakil SM, et al. Long-Term Effects of 4 Popular Diets on Weight Loss and Cardiovascular Risk Factors: A Systematic Review of Randomized Controlled Trials. Circ Cardiovasc Qual Outcomes 2014;7:815-27.
6. Feinman RD, Pogozelski WK, Astrup A, et al. Dietary carbohydrate restriction as the first approach in diabetes management: Critical review and evidence base. Nutrition 2015;31(1):1-13.
7. Meng Y, Bai H, Wang S, et al. Efficacy of low carbohydrate diet for type 2 diabetes mellitus management: A systematic review and meta-analysis of randomized controlled trials. Diabetes Res Clin Pract 2017;131:124-31.
8. Ebe K, Ebe Y, Yokota S, et al. Low Carbohydrate diet (LCD) treated for three cases as diabetic diet therapy. Kyoto Medical Association Journal 2004;51:125-29.
9. Bando H, Ebe K, Nakamura T, et al. Low Carbohydrate Diet (LCD): Long and short-term effects and hyperketonemia. Glycative Stress Research. 2016;3(4):193-204.
10. Muneta T, Kawaguchi E, Nagai Y, et al. Ketone body elevation in placenta, umbilical cord, newborn and mother in normal delivery. Glycative Stress Research 2016;3(3):133-140.
11. Bando H, Ebe K, Muneta T, et al. Effect of low carbohydrate diet on type 2 diabetic patients and usefulness of M-value. Diabetes Res Open J 2017;3(1):9-16.
12. Ebe K, Bando H, Muneta T, et al. Effect of low carbohydrate diet (LCD) for diabetic patients with hypertriglycemia. Endocrinol Metab 2017;1(1):104.
13. Bando H, Ebe K, Muneta T, et al. Clinical Effect of Low Carbohydrate Diet (LCD): Case Report. Diabetes Case Rep 2017;2:124.
14. Schlichtkrull J, Munck O, Jersild M, et al. The M-value, an index of blood sugar control in diabetics. Acta Med Scand 1965; 177:95-102.
15. Service FJ, Molnar GD, Rosevear JW, et al. Mean amplitude of glycemic excursions, a measure of diabetic instability. Diabetes 1970;19:644-55.
16. Moberg E, Kollind M, Lins PE, et al. Estimation of blood-glucose variability in patients with insulin-dependent diabetes mellitus. Scand J Clin Lab Invest 1993;53:507-14.
17. Siegelaar SE, Holleman F, Hoekstra JB, et al. Glucose Variability; Does It Matter? Endocrine Reviews 2010; 31(2):171-82.
18. Service FH. Glucose variability. Diabetes 2013;62(5):1398-404.
19. Monnier L, Colette C. Glycemic Variability:Can We Bridge the Divide Between Controversies?. Diabetes Care 2011;34(4):1058-59.
20. Baghurst P. Calculating the mean amplitude of glycemic excursion from continuous glucose monitoring data: an automated algorithm. Diabetes Technol Ther 2011;13(3):296-302.
21. Yanai H. Four step excel statistics, 4th Edition, Seiun-sha Publishing Co.Ltd, Tokyo 2015.
22. Japan Diabetes Association. Diabetes clinical practice guidelines Based on scientific evidence 2013.
23. The Ministry of Health and Welfare, Japan. National Health Nutrition Survey Results 2015.
24. American Diabetes Association (ADA). Nutrition recommendations and interventions for diabetes. Diabetes Care 2013; 36(1):S12-32.
25. Ceriello A, Esposito K, Piconi L, et al. Oscillating glucose is more deleterious to endothelial function and oxidative stress than mean glucose in normal and type 2 diabetic patients. Diabetes 2008;57:1349-54.
26. Wolever TM, Jenkins DJ, Jenkins AL, et al. The glycemic index: methodology and clinical implications. Am J Clin Nutr 1991;54:846-54.
27. Brouns F, Bjorck I, Frayn K, et al. Glycemic index methodology. Nutr Res Rev 2005;18: 145-71.
28. Ludwig DS. The glycemic index: physiological mechanisms relating to obesity, diabetes, and cardiovascular disease. JAMA 2002;(287):2414-23.
29. Soong YY, Lim J, Sun L, et al. Effect of co-ingestion of amino acids with rice on glycemic and insulinemic response. Br J Nutr 2015;114(11):1845-51.
30. Villegas R, Liu S, Gao YT, et al. Prospective study of dietary carbohydrates, glycemic index, glycemic load, and incidence of type 2 diabetes mellitus in middle-aged Chinese women. Arch Inter Med 2007;167: 2310-16.
31. Nanri A, Mizoue T, Noda M, et al. Rice intake and type 2 diabetes in Japanese men and women: the Japan Public Health Center-Based Prospective Study. Am J Clin Nutr 2010;92:1468-77.
32. Mohan V, Radhika G, Sathya RM, et al. Dietary carbohydrates, glycemic load, food groups and newly detected type 2 diabetes among urban Asian Indian population in Chennai, India (Chennai Urban Rural Epidemiology Study 59). Br J Nut 2009;102:1498-06.
33. Kawabata A, Yagi M, Ogura M, et al. Postprandial blood glucose level after intake of a bowl of rice topped with beef. Glycative Stress Research 2015;2(2):67-71.
34. Teo K, Chow CK, Vaz M, et al. PURE Investigators-Writing Group, The Prospective Urban Rural Epidemiology(PURE) study: examining the impact of societal influences on chronic noncommunicable diseases in low-, middle-, and high-income countries. Am Heart J 2009;158(1):1-7.e1.
35. Miller V, Yusuf S, Chow CK, et al. Availability, affordability, and consumption of fruits and vegetables in 18 countries across income levels: findings from the Prospective Urban Rural Epidemiology (PURE) study. Lancet Glob Health 2016;4(10):e695-703.
36. Mente A, Dehghan M, Rangarajan S, et al. Prospective Urban Rural Epidemiology (PURE) study investigators Association of dietary nutrients with blood lipids and blood pressure in 18 countries: a cross-sectional analysis from the PURE study. Lancet Diabetes Endocrinol 2017.
37. Dehghan M, Mente A, Zhang X, et al. Prospective Urban Rural Epidemiology (PURE) study investigators Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study. Lancet 2017.
38. International Diabetes Federation (IDF). Diabetes Atlas. (6th ed.) 2013.
39. Kwon YJ, Lee HS, Le JW, et al. Association of carbohydrate and fat intake with metabolic syndrome. Clinical Nutrition 2017.
40. Ogurtsova K, Huang Y, Linnenkamp U, et al. IDF Diabetes Atlas: Global estimates for the prevalence of diabetes for 2015 and 2040. Diabetes Res Clin Pract 2017;128:40-50.
41. International Diabetes Federation (IDF). Standards of Medical Care in Diabetes-2015. Diabetes Care 2015;38:S1-S94.