Diabetes Mellitus and its Potential for Health Improvements
Diabetes Mellitus has been identified as an area with promising potential for health improvements due to its rapidly rising prevalence, distinctive contribution to disease burden both globally and within Australia, and increasing importance in public health policy streams.
The Importance of Integrated Strategy for Diabetes Mellitus
Diabetes mellitus is a major cause of disease in Australia, according to the National Health Priority Areas (NHPA). An integrated strategy that includes prevention and management on a continuum in addition to therapy is important to lower the incidence and prevalence of the disease.
The Role of Carnitine in Diabetes Mellitus
A nutrient of focus is carnitine. Carnitine is known for its performance in transporting long-chain fatty acids into mitochondrial matrix of beta-oxidation.
Carnitine and Insulin Resistance
The essential nutrient is also necessary for the outward flow of acyl groups out of the mitochondria (Ringseis, Keller & Eder, 2011 p. 23). In an article outlining the role of carnitine regarding the assurance of glucose levels being at equilibrium and insulin sensitivity, it is explained that the accumulation of acyl-CoA directly correlates with the development and increase of insulin resistance.
Carnitine Supplementation for Insulin Resistance
Regarding treatment and prevention, carnitine supplementation has been identified as a viable option for the prevention and to combat insulin resistance present in Type 2 Diabetes, as well as supporting glucose homeostasis within cells. According to the aforementioned research article; more recent studies point toward carnitine as a causative factor for insulin resistance, when present in insufficient amounts, specifically linked to when an individual is obese and therefore in chronic metabolic stress. Which is known to reduce as well as be reversed, by carnitine supplements (Ringseis, Keller and Eder, 2011 p. 37).
Carnitine and its Importance for Normal Tissue Function
Carnitine is a water-soluble quaternary amine and is essential for normal tissue function. Carnitine synthesis is dependent on the availability of several co-factors including the micronutrients, Vitamin C, Vitamin B6 and iron; a deficiency in these nutrients can lead to carnitine deficiency, which is a result of the deficiency comorbidities. L-Carnitine in various tissues is managed and kept within the normal range because as a result of renal processes of absorption through cat-ion transporters, all dependent on carnitine's availability in the diet (Bae et al., 2015 p. 11).
Sources of Carnitine
The main sources of carnitine are found in animal products, such as; meat (red meat) and dairy products. However, surprisingly vegetarians, who consume less carnitine from diet, due to reduced consumption of meat products, still maintain an adequate level of carnitine, which indicates that the human body can adequately synthesise carnitine. This is estimated to be at 0.19mg per kg body weight (Ringseis, Keller & Eder, 2011 p. 45). Generally carnitine is absorbed from foods, and can also be biosynthesized from lysine and methionine. However, the level of carnitine in the body is chiefly dependent on its prevalence in diet (Bae et al., 2015 p. 34).
The Potential of L-Carnitine in Diabetes Complications Prevention
A 2012 Nutrition Research article expands on the possibility of L-carnitine having an effect in preventing complications relating to type 1 and type II diabetes. The article stated that through observations of lower L-carnitine levels, an increase of studies have risen focusing on patients with diabetes and carnitine as a supplement and the 'therapeutic implications' of that (Liepinsh et al., 2012 p. 12). Findings have shown that the effects of L-carnitine in healthy subjects aren't straight forward and the narrow ratio of human adult studies, specifically with diabetic patients at various stages of being affected by the burden of disease (Liepinsh et al., 2012 p. 13)
Research on Carnitine, Glucose Tolerance, and Insulin Sensitivity
In a controlled study undertaken by Ringseis, Keller and Eder. Where 16 studies were of individuals with metabolic disorders, 6 studies included healthy individuals and an animal study on 19 rats were subjects for testing of glucose tolerance and insulin sensitivity and how the presence of carnitine links to their association. Out of these studies a total of ten studies were considered suitable for evaluation and for results to be drawn from and discussed. The study characteristics are as follows; randomized control trial with a set timeframe that fluctuated depending on the subject of focus (Ringseis, Keller & Eder, 2011 p. 10). In this article Ringseis et al., states that carnitine and it's by products (ALC and PLC) strengthen the utlisation of glucose by acting as a catalyst in for Pyruvate dehydrogenase complex (PDHC), which is crucial in the oxidation process of glucose. Therefore, carnitine strongly reduces intramitochondrial acetyl-CoA levels resulting in a 10- to 20-fold decrease in the acetyl-CoA/ CoA ratio. This mechanism of action of carnitine and ALC is supposed to be responsible for the enhancement of glucose utilization in both healthy and type 2 diabetic subjects (Liepinsh et al., 2012 p. 20).
Effectiveness of L-Carnitine as a Supplement in Diabetes Mellitus
In a hospital based study, Bashi and Al-Farha (2010) sought to find out the effectiveness of L-carnitine as a supplement in combination with other medications for patients with diabetes mellitus. Hospital volunteers (54) in this study all took the supplement of L-carnitine and had several tests throughout. These tests measured fasting plasma glucose (FPG), Hba1c, serum creatinine and urea and all of these showed a lowering effect by the end of the study due to the L-carnitine supplement (Bashi and Al-Farha, 2010 p.16). It is stated in the study that these findings could be due to the L-carnitine activating the receptors in the kidney for carnitine and increase β-oxidation and action of the kidney. This study has limitations in that it's framework is weak and validity is affected because of it. Were these findings to be more solid, another study would need to be conducted, with the use of a double blind RCT so major differences can be perceived between a control and intervention group. However, these findings can still have a strong practical application as shown by all p-values being at (p).
