Diabetes

Diabetes, like many other NCDs, is on the rise.  Classifiable into one of two main categories, 90% of the 328 million people currently living with the disease are diagnosed with type 2 diabetes. 

Diabetes occurs when the body is no longer able to manage its own blood glucose levels, due to insufficient insulin production diabetes may be classified according to one of two types. Diabetes mellitus type 1 is an endocrine disorder resulting in an absolute insulin deficiency due to the destruction of insulin producing (beta cells) of the pancreas.¹ Often developing in childhood, sufferers of diabetes mellitus type 1 are unable to metabolize carbohydrates, proteins and fats normally results in hyperglycemia.  Acute hyperglycaemia results in polyuria (excessive urine excretion), polydipsia (thirst), constant hunger, weight loss, altered vision and a fatigued state and eventual diabetic ketoacidosis and hyperosmolar hyperglycemia state.^1-3,5 In contrast type 2 diabetes occurs when the body exhibits varying degrees of resistance or deficiency in circulating insulin. ⁴ Formally known as adult onset diabetes; this condition is directly correlated with obesity and physical inactivity. Sufferers exhibit similar symptoms to type 1, with a more gradual onset, taking a number of years to manifest.^1,5

Causal factors 

Type 1

Selective beta cell destruction is the result an autoimmune response, driven by the presence of auto antibodies to either islet cells; insulin, GAD65 or tyrosine phosphatises.  Antibody driven destruction of beta cells is accredited to a combination of polygenic susceptibility and environmental exposure.^2,3 Approximately 50% of genetic susceptibility is accredited to presence of HLA on chromosome 6.³ Environmental triggers including diet, viral exposure and vitamin D deficiency; which may occur in utero or postnatally; are through to precipitate onset in genetically susceptible individuals.³

Type 2

Metabolic risk factors associated with development of diabetes mellitus type 2 include; obesity (defined as having a BMI exceeding 30), prediabetes (the presence of higher than average fasting glucose levels) metabolic and polycystic ovary syndrome as well as gestational diabetes.⁵ Lifestyle risk factors include a diet high in processed meat and high GI foods in addition to a sedentary life style and smoking.  Lower socioeconomic status is also closely correlated with its development, with more than 80% of cases occurring in low income countries.^5-7

Interactive Plot avalible at
http://healthintelligence.drupalgardens.com/content/prevalence-diabetes-world-2013

A few facts too put this all into perspective

Currently 347 million people have diabetes worldwide and is set to become the 7^th leading cause of death by 2030.²

In 2012 along, 1.5 million people died of diabetes, 80% of which was in low and middle income countries.²

Type 2 diabetes makes up 90% of cases; which means that most of these cases are preventable.²

Previously prevalence of type 2 in children was rare; currently almost half of all new diagnosis are in children.²

Not only is it causing premature death; diabetes is a leading cause of blindness, amputation and kidney failure.

The majority of causes of type 2 are preventable with moderate intensity physical activity, and a healthy diet.²

Within developing countries...

In 2013 the countries with the highest prevalence of diabetes; 
Tokelau (37.5%), Federated States of Micronesia (35%), Marshall Islands (34.9%), Kiribati (28.8%), Cook Islands (25.7%), Vanuatu (24%), Saudi Arabia (23.9%), Nauru (23.3%), Kuwaite (23.1%) and Quatar (22.9%).²

Most of these countries are located within the Western Pacific, Middle East or Northern African region.²

In Africa, diabetes is responsible for 76% of deaths occurring under the age of 60.²

Furthermore 1 in 10 adults in both Northern Africa and the Middle east have diabetes (34,571 people).²

Within the western pacific regions, 138 195 people are diagnosed with diabetes; a prevalence of 8.6%.² 

In contrast Europe has the highest prevalence of type 1 diabetes in children.²

References

1. Atkinson MA, Eisenbarth GS, Michels AW. Type 1 diabetes. Lancet 2014;383(9911):69-82.

2. IDF. IDF Diabetes Atlas sixth addition [Internet] 2013.  [cited 2015 Mar 26] Available from:http://www.idf.org/diabetesatlas

3. Redondo MJ, Jeffrey J, Fain PR, Eisenbarth GS, Orban T. Concordance for islet autoimmunity among monozygotic twins.N Engl J Med. 2008; 359(26):2849.

4. Hu G1, Lindström J, Valle TT, Eriksson JG, Jousilahti P, Silventoinen K, Qiao Q, Tuomilehto J. Physical activity, body mass index, and risk of type 2 diabetes in patients with normal or impaired glucose regulation. Arch Intern Med. 2004; 164(8):892-6.

5. Paneni F, Beckman JA, Creager MA, Cosentino F. Diabetes and vascular disease: pathophysiology, clinical consequences, and medical therapy: part I. Eur Heart J.2013;34(31):2436-2443.

6. Kumari M1, Head J, Marmot M. Prospective study of social and other risk factors for incidence of type 2 diabetes in the Whitehall II study. Arch Intern Med. 2004;164(17):1873-80.

7. Wannamethee SG1, Shaper AG, Lennon L, Morris RW. Metabolic syndrome vs Framingham Risk Score for prediction of coronary heart disease, stroke, and type 2 diabetes mellitus. Arch Intern Med. 2005; 165(22):2644-50.

8. Perreault L, Pan Q, Mather KJ, Watson KE, Hamman RF, Kahn SE; Diabetes Prevention Program Research Group. Effect of regression from prediabetes to normal glucose regulation on long-term reduction in diabetes risk: results from the Diabetes Prevention Program Outcomes Study. Lancet. 2012;379(9833):2243-51.

9. Stringhini S1, Tabak AG, Akbaraly TN, Sabia S, Shipley MJ, Marmot MG, Brunner EJ, Batty GD, Bovet P, Kivimäki M. Contribution of modifiable risk factors to social inequalities in type 2 diabetes: prospective Whitehall II cohort study. BMJ. 2012;345.