Prevalence, Aetiology and Pathology of Type 2 Diabetes

Introduction

A summary of the prevalence, aetiology and pathology of type 2 diabetes

What is diabetes?

• Diabetes is a group of conditions characterised by high blood glucose
• Type 2 diabetes occurs due to insufficient insulin secretion and/or insulin resistance
• Hyperglycaemia results from defects in insulin production, insulin activity or both
• 4.6 million people have diabetes in the UK

	Type 2 Diabetes
Pathophysiology	Tissue insulin resistance (liver, muscle, adipose) driven by obesity Compensatory hyperinsulinemia & eventual β-cell failure
Presentation	Gradual onset, symptoms subtle or absent Anti-body negative	Going to the toilet a lot – polyuria Being thirsty – polydipsia Unplanned weight loss, Blurred vision
Risk factors	Age, obesity, family history, ethnicity, history of gestational diabetes mellitus /Polycystic ovary syndrome, physical inactivity, diabetogenic drugs, low socioeconomic status,
Treatment	Weight loss, Healthy eating and exercise Different medications including insulin

Short term complications

• Hyperosmolar hyperglycaemia state (common)
• Diabetic ketoacidosis (uncommon)

Long term complications

• High  blood sugar, heart disease, strokes,
• Diabetic retinopathy which can result in blindness.
• kidney failure, poor blood flow in the limbs which may lead to amputations.

Type 2 diabetes

• Primarily occurs due to obesity exercise deficiency, however some people are more genetically at risk.
• Makes up about 90% of cases, the other 10% are diabetes mellitus type 1 and gestational diabetes.
• Due to insufficient insulin production from beta cells and increased insulin resistance. Insulin resistance occurs primarily within the muscles, liver and fat tissue.

Diagnosis of diabetes is by blood tests such as:

• fasting plasma glucose ≥ 7mmol/L

• random or 2-hour O-GlcNAc-modified protein levels  ≥11.1mmol/L

• Hba1c ≥ 48 mmol/mol

 

Provide a brief summary of the overall aims of treatment

Treatment options for Type 2 diabetes

• Medications
• Diet and lifestyle
• Bariatric surgery

Medications

• Improves insulin sensitivity
• Stimulates insulin production
• Increase amount of glucose in urine

Diet and lifestyle

• Weight loss is the primary goal for people who are overweight or obese
• 5% weight loss improves HbA1c by 7mmol/mol (0.6%) reduction in HbA1c in Type 2 diabetes
• 5% weight loss also improves CVD risk factors such as blood pressure and cholesterol
• Different dietary approaches can achieve weight loss and improve glycaemic control
• Healthy eating, Low carbohydrate diets, Meal replacements, Mediterranean diets

Bariatric surgery

• 30-60% remission rate depending on the type of surgery
• Median diabetes-free duration is about 8 years
• Reports of people going up to 15years without diabetes

Case study details and reason for referral

Patient details – A.H 58-year-old south Asian male taxi driver

Referral details – patient attended diabetic clinic for a routine review

ASSESSMENT PHASE

Nutritional Assessment

Anthropometry

• Weight: 82.2Kg, height 1.58m, BMI: 32.9kg/m², WC 93cm (Obese, Class I – WHO, 2004).
• As from South Asian background his obesity classification puts him as high risk of experiencing obesity related co-morbidities.
• Obesity increases insulin resistance which increases his risk of experiencing raised HBA1C, further increasing his risk of micro and macro vascular complications of diabetes.
• A measure of his waist circumference would identify abdominal adiposity and potential further insulin resistance.

Biochemistry

Biochemical Markers	Current Levels	Reference Range/Target	Interpretation
HbA1c	68.3 mmol/mol	Non-diabetic 20 – 42 mmol/mol Prediabetes  42 – 47 mmol/mol Good control 48 – 59 mmol/mol Diabetes ≥ 48 mmol/mol (Diabetes UK)	HbA1c 68.3mmol/mol. This is above the recommended range for Type 2 diabetes which is 48mmol/mol
Creatinine	150 µmol/l	40-130 µmol/L	Above the reference range. Indicates impaired renal function.
Na	135 mmol/L	133 – 146 mmol/L (Gaw et al., 2013)	Within the reference range (normal)
K	4.6 mmol/l	3.5 – 5.3 mmol/L (Gaw et al., 2013)	Within the reference range (normal)

A.H Results of fasting laboratory tests (drawn 5 days before clinic visit:

Lipid Profile	Current Levels	Reference Range /Target	Interpretation
Total cholesterol	6.0 mmol/l	<4 mmol/l (JBS2)	Total cholesterol should be <4 mmol/l (JBS2, 2005)
Non-HDL cholesterol	5.4 mmol/l	<2.5 mmol/L (JBS3)	His non-HDL cholesterol is higher than the target set by JBS3 (2014) which recommends a non-HDL cholesterol of <2.5 mmol/l.
HDL-cholesterol	0.6 mmol/l	>1.0 mmol/L (M) , >1.2 mmol/L (Joint ESC Guidelines, 2012)	HDL are below the target indicating a high non-HDL cholesterol. This further increases his risk of CVD events.
Plasma triglyceride	1.6 mmol/l	<1.7 mmol/L (Joint ESC Guidelines, 2012)	Triglycerides are below the recommended target increasing the risk of CVD events.

His raised HbA1c increases his risk of experiencing the micro and macro vascular complications of diabetes which are further compounded by a high non-HDL cholesterol level which increases his risk of experiencing events related to cardiovascular disease.

Clinical

• The patient has Type 2 diabetes and it would be helpful to understand the length of time he has been diagnosed.
• He is prescribed Metformin 1000mg twice daily, Ramipril 5mg once daily, Simvastatin 40mg once daily, Bendrofluazide 2.5mg once daily, Amlodipine 5mg once daily and Aspirin 75mg once daily.
• Metformin is a biguanide which decreases gluconeogenesis and increases the peripheral utilisation of glucose. It is effective only if there are some residual function of pancreatic islet cells. It is the first choice in overweight patients.
• Ramipril is one of the antihypertensive medications and was prescribed to control his blood pressure  as his history says has been diagnosed of hypertension.
• Simvastatin to control blood lipid levels which competitively inhibits co-enzyme A (HMG CoA reductase which is involved in cholesterol synthesis.
• Bendrofluazide is a medication used to control the High blood pressure it works by making the kidney excrete more water (a diuretic) therefore reduces the blood pressure.
• Amlodipine is also one group of medication hey call them calcium channel blockers and also used to lower the blood pressure.
• Aspirin is a blood thinner and it works by inhbiting the platelet function (antiplatelet) tends to reduce the risk of heart attacks and strokes. Aspirin has been prescribe beach he was diagnosed to have ischaemic heart disease.
• Blood pressure = 122/69mmHg which is considered controlled blood pressure.

Dietary

Qualitative Dietary Assessment

• A dietary assessment reveals Mr A.H regularly consumes traditional south Asian meals managing 3 meals a day with snacks in-between and he consumes adequate dairy.
• His food choices are high in fat, sugar and refined carbohydrates as he regularly consumes biscuits and sweet drinks.
• His portion sizes are large as he often opts for 2 portions (e.g. chicken biryani)
• His fibre intake is low and not meeting the recommended intake of 5 portions of fruit/vegetables per day.

Quantitative Dietary Assessment

• His energy intake is 4774 kcal
• His protein intake is 176 g
• His fluid intake is 2187 ml

Requirement for Energy, Protein and Fluid

• His requirement for energy is =2100 kcal
• BMR = 1654.86 x 1.63 (PAL as low activity) = 2697 (-600 kcal to induce negative energy balance) (HENRY 2005, NICE Obesity, 2014)
• His requirement for protein is 61.65g (0.75 X 82.2) (RNI for protein, COMA 1991)
• Fluid requirements 2500 ml (EFSA, 2010, as the case is free living)

He is not metabolically stressed, has a low activity lifestyle and a 600kcal energy deficit has been incorporated to achieve weight loss.

(NICE; CG43 2006 and 2010)

Henry, 2005)

Economic/Lifestyle/Psychosocial

He is a full-time taxi driver and spends most of his spare time with his family.

Identifying physical activity is important in estimating requirements and for future treatment suggestions.

His wife and daughter take care of shopping, so it would be useful to include them in consultations with patient consent.

Persuading them to adapt and change cooking methods will be helpful in reducing his fat intake.

He is reluctant to consider altering medication due to concerns regarding employment.   This may help in motivating him to lose weight which would improve his insulin sensitivity.

Attendance at structured education classes would be useful for him and he should have access to culturally appropriate advice and written information.

SUMMARY OF ASSESSMENT

• The case has poorly controlled type 2 diabetes and increased risk of CVD. He has been prescribed OHGA (metformin and pioglitazone to increase sensitivity to insulin ) and simvastatin(to decrease cholesterol ) and ramipril and amlodipine(to decrease hypertension ) and aspirin(primary prevention of cvs events ) and bendrofluazide (to decrease the blood pressure).

• This is secondary to obesity and excess intake of energy.

• This is evidenced through a BMI 32.9 kg/m2 (obese class 1) which indicates high risk due to south Asian ethnicity. His HBA1C 68.3 mmol/mol; total Cholesterol 6.0 mmol/l, non-HDL cholesterol: 5.4 mmol//l HDL 0.6 mmol/l

• Treatment options are to consider weight loss of a minimum of 5% through reducing overall energy/fat intake and portion sizes. Adapting to a Mediterranean diet will help reduce lipid levels/CVD risk.  Increasing physical activity will further improve insulin sensitivity and reduce his HBA1C.

NUTRITION AND DIETETIC DIAGNOSIS PHASE

• Excessive energy, fat and carbohydrate intake contributing to poorly controlled diabetes/high risk of CVD. Perpetuated by large portion sizes and high fat/sugar diet. It is evidenced by a BMI > 30kg/m2, HbA1c > 48mmol/mol.

Patient Specific Outcomes

Over the next 6 weeks and by consistent consultation with Mr. A.H, provision of an individualised approach that is culturally sensitive and supports long term health/wellbeing:

• 5% weight loss through reduction of energy intake achieving weight loss of 0.5-1kg per week.

• Reduce HBA1c nearer to the target of 48-53 mmol/mol.

• Increase physical activity to 30 minutes 5 days a week.

• Offer structured education through attending group sessions.

Over the next 6-12 months:

• Sustain weight loss through modified dietary intake to achieve 10% weight loss.

• Increase in physical activity to 150 minutes three times per week.

• Settle at HBA1C of between 48-53 mmol/mol over the next 12 months (NICE, 2015)

• Reduce CVD risk through an overall reduction in blood lipids through alteration of medication and modifying dietary intake and lifestyle.

Treatment plan

• 5% weight loss, reduction in blood lipids and HBA1C

• Reduce portion sizes at meal times, particularly focusing on carbohydrate portions at lunch/evening.

• Reduce his saturated fatty acid/additional fat intake including butter in cooking/bread.

• Switch to a lower fat/skimmed milk consistently.

• Reduce intake of red meat and replace with plant-based protein sources such as pulses or animals such as oily fish/lean chicken.

• Suggesting a plant stanol spread.

• Remove parathas for chapattis instead to further reduce his fat intake.

• Stop sugar sweetened beverages and offer an alternative sweetener. Stop snacking on biscuits and suggest fruit.

• Consider increasing his intake of beta-glucans and soluble fibre through consuming an oat-based cereal for breakfast such as porridge and oat cakes.

• Increase his micronutrient (fibre) intake and consumption of 5 fruit/vegetables a day.

Implementation

• Increase physical activity – trips to the park/playground with grandchildren. Walking daily – maybe at lunchtime. Consider a walking group – exercise on prescription for example.

• Avoid snacking at work.

• Involve the wife and two children in achieving lifestyle changes and invite them to consultations.

• Enrol in structured education to improve motivation towards managing his diabetes.

• Culturally appropriate written information reinforcing the recommended dietary changes and lifestyle modifications.

Appendices

Energy

• 11.4W + 541H – 137

• BMR= 11.4 (82.2) + 541(1.58) –137
• 937.08 + 854.78 – 137
• BMR = 1654.86 kcals
• 1654.86 x 1.63 (PAL as low activity)  = 2697

– 600 kcals for weight loss = 2097 kcals/day

Protein

• Her requirement for protein is calculated using the RNI for protein of 0.75/kg/bw.
•  (COMA, 1991)

Fluid

• 2500 ml per day.
• The EFSA in 2010 stated that this is an adequate fluid intake for females.
• EFSA is appropriate as the patient is free living and not metabolically stressed.

References

1. WHO (2004) Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Report of a WHO Consultation. WHO Technical Report Series 854. https://www.who.int/nutrition/publications/bmi_asia_strategies.pdf
2. Diabetes.co.uk. (2019). What is HbA1c? – Definition, Units, Conversion, Testing & Control. [online] Available at: https://www.diabetes.co.uk/what-is-hba1c.html [Accessed 19 Jun. 2019].
3. Gaw, A., Murphy, M., Srivastava, R., Cowan, R., O’Reilly, D., Britton, R. and Tibbitts, R. (2013). Clinical Biochemistry. 5th ed. Edinburgh: Churchill Livingstone/Elsevier.
4. Joint British Societies ‘Guidelines (JBS2, 2005) on prevention of CVD in clinical practice. Heart 2005;91:v1-v52. https://www.chss.org.uk/documents/2014/10/joint-british-societies-guidelines-on-prevention-of-cardiovascular-disease-in-clinical-practice-jbs2-pdf.pdf
5. Joint British Societies’ consensus (JBS3, 2014) recommendations for the prevention of cardiovascular disease. Heart 2014;100:ii1-ii67. http://dx.doi.org/10.1136/heartjnl-2014-305693
6. Joint European Society of Cardiology (Joint ESC Guidelines, 2012) European Heart Journal, Volume 33, Issue 17, September 2012, Page 2126, https://doi.org/10.1093/eurheartj/ehs254
7. Henry, C. J. K. (2005) “Basal metabolic rate studies in humans: measurement and development of new equations,” Public Health Nutrition, Cambridge University Press, 8(7a), pp. 1133–1152. https://doi.org/10.1079/PHN2005801
8. National Clinical Guideline Centre (UK). Obesity: Identification, Assessment and Management of Overweight and Obesity in Children, Young People and Adults: Partial Update of CG43. London: National Institute for Health and Care Excellence (UK); 2014 Nov. (NICE Clinical Guidelines, No. 189.) Available from: https://www.ncbi.nlm.nih.gov/books/NBK264165/
9. Department of Health – Committee on Medical Aspects of Food Policy (1991). Dietary reference values for food energy and nutrients for the United Kingdom. London: H.M.S.O. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/743786/Dietary_Reference_Values_for_Food_Energy_and_Nutrients_for_the_United_Kingdom__1991_.pdf
10. EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA); Scientific Opinion on Dietary reference values for water. EFSA Journal 2010; 8( 3):1459. [48 pp.]. doi:10.2903/j.efsa.2010.1459.