Prevention of diabetes

There is a tsunami of type 2 diabetes mellitus (T2D) threatening to engulf the nation, swallowing up NHS resources in its path; yet T2D is a largely preventable disorder which requires simple lifestyle measures in many cases to halt the progress. We discuss some of the key risk factors and how to identify those at risk

In 2012, the National Institute for Health and Care Excellence (NICE) published its guideline on the prevention of diabetes. The key recommendation within this document was that all people over 40 should be offered screening along with anyone age 25-39 of South Asian, Chinese, African-Caribbean, black African origin and those from other high-risk black and minority ethnic groups. The guideline also advised that people who were at increased risk should also be risk assessed; the factors that increased the risk of developing T2D included obesity, polycystic ovary syndrome or a history of gestational diabetes.¹

CASE STUDY

Beth is 52 years old. She has a BMI of 35.06mg/m2 and her waist measurement is 92cm. She recently attended for an NHS Health Check and her blood tests showed a total cholesterol of 6.3mmol/l, triglycerides of 2.3mmol/l and an HDL cholesterol of 1.2mmol/l. Her blood pressure was 127/88mm/Hg. Her fasting blood glucose was 6.0mmol/l. She has a family history of type 2 diabetes with her father, two paternal uncles and a maternal aunt all having the condition; her mother had a myocardial infarction when she was aged 67. She has never smoked and enjoys only an occasional glass of wine on special occasions. She is a business woman running her own human resources company. She is divorced with no children: she explained that a history of polycystic ovary syndrome had made it hard to conceive but she had decided she was happy to remain childless once the cause had been identified.

After her blood results were received her NHS Health Check was completed using the Qrisk cardiovascular risk assessment tool.^2,3 The practice nurse shared the result shown on screen:

• Your 10-year QRISK® score = 4.2%
• The score of a healthy person with the same age, sex, and ethnicity = 2.6%
• Relative risk = 1.6
• Your QRISK® Healthy Heart Age = 58

The practice nurse had already explained that a score of 10% or more suggested an increased level of risk which would need treating. As a result, Beth was quite happy with this result, despite the fact that overall she showed an increased level of risk for her age. However, the practice nurse suggested that with her family history and other risk factors (obesity and polycystic ovary syndrome) she should undergo a specific risk assessment for type 2 diabetes. After discussion of the implications of the results of the risk assessment Beth agreed that this was a good idea. Her father had died of a stroke related to poor diabetes control and prior to his death had been diagnosed with diabetic retinopathy and renal impairment. His quality of life was poor and he had been unable to drive or work for several years. He was only 65 when he died. Beth was keen to find out what she could do to avoid developing diabetes.

There are a number of validated tools available to assess the risk of developing type 2 diabetes, specifically the Cambridge diabetes risk score,4 and the Leicester practice score,5 which are mentioned in the NICE guidelines.¹ QDiabetes has also now been validated to assess the risk of diabetes.^6,7 Diabetes UK also has an online assessment tool for self-assessment of T2D risk, available at http://riskscore.diabetes.org.uk/start. As Beth was already in the surgery her risk was calculated using QDiabetes, which is easily accessed online. Her results were shown on screen:

• Your 10-year QDiabetes® score = 22.4%
• The score of a typical person with the same age, sex, and ethnicity = 3.7%
• Relative risk = 6.1

This result was obviously of considerable concern. Not only did Beth have a greater than 1: 5 risk of developing T2D in the next ten years, her risk was over six times that of an ‘average’ person of the same age, sex and ethnicity. In people who are found to be at high risk of developing T2D, NICE advises that a blood test should be carried out to further quantify that risk.¹ The test might be a fasting blood glucose, an HbA1c or a glucose tolerance test. A fasting blood glucose between 5.6mmol/l and 6.9mmol/l, an HbA1c of 42-47mmol/mol or a positive glucose tolerance test would confirm Beth’s high risk status. Beth’s recent fasting blood test result was 6.0mmol/l, indicating impaired fasting glycaemia and with her other measurements, suggesting that she had metabolic syndrome. The International Diabetes Federation has defined metabolic syndrome as being present when someone who is centrally obese and/or has a BMI of 30kg/m² has two of the following risk factors:⁸

• Raised triglycerides ≥ 1.7 mmol/l) or specific treatment for this lipid abnormality
• Reduced HDL cholesterol
• Raised blood pressure systolic BP ≥ 130 or diastolic BP ≥ 85 mmHg or treatment of previously diagnosed hypertension
• Raised fasting plasma glucose (FPG) ≥ 5.6 mmol/l, or previously diagnosed type 2 diabetes.

People with metabolic syndrome have a fivefold increased risk of developing type 2 diabetes.⁹

Having heard all of this and having seen the problems that T2D could cause first hand, Beth was keen to find out what she could do to prevent herself from developing the condition.

The NICE guidelines include advice on how to prevent or delay the onset of T2D and the focus is strongly on lifestyle advice.¹ This includes encouraging people to become more physically active and to make dietary changes to help the individual to reach and maintain a healthy body mass index. Advice and support should be offered to achieve and maintain these changes for life.

NICE recommends that group interventions for 10-15 people aimed at improving lifestyle behaviours should be offered. Unfortunately there was nothing of this description available in Beth’s area; however, Beth stated that she would not be able to attend anything on a regular basis anyway but would be prepared to work with the practice nurse to make the changes that were clearly needed. She admitted that she probably knew what to do; it was doing it that was her biggest challenge. The ultimate aim was now to build Beth’s confidence and her ability to deal with the challenges she was facing both now and in the future.

Beth admitted that she worked long hours, travelled a great deal and had little time (nor inclination) to exercise. She ate ‘on the hoof’ grabbing coffee and croissants for breakfast at the station, snacking throughout the day and then having a restaurant meal or a takeaway in the evening. She rarely cooked but said she enjoyed her food and liked to ‘reward’ herself with ‘something nice’ at the end of a hard day.

There is a wealth of information available to the general public about how to lose weight and be more physically active, yet the message does not appear to be getting through. In spite of the amount of information available through NHS Choices, from surgeries and pharmacies and via commercial weight loss organisations the prevalence of obesity continues to rise.¹⁰ Even when people have decided they need help to lose weight, they may come with specific ideas including going ‘sugar-free’, following a low carbohydrate diet, using intermittent fasting (the 5: 2 diet) or even very low calories diet (VLCD) of no more than 800 calories per day, often using shakes and bars as the main source of nutrition. Despite there being some evidence for each of these approaches,11–14 the NICE guidelines on managing obesity recommend the standard approach of eating a nutritionally sound diet combined with increasing activity levels.¹⁵ As in all areas of healthcare, however, it is vital that a personalised approach is taken and that individual preference is taken into account. This is something that NICE recognises as it recommends that any intervention is personalised to the individual’s beliefs, needs and preferences.

Beth was interested in the VLCD approach to weight loss as she felt that avoiding ‘normal’ food altogether might be the approach that would work best for her. The review of this approach by Lean et al,14 demonstrated that in people using a VLCD approach, an average weight loss of 17kg was measured over a 14 week period although losses of up to 40kg were seen. Follow up 12 months later showed that one in three participants had kept off at least 15kg. NICE does not endorse the use of VLCDs,15 although according to these guidelines Beth would qualify for referral for bariatric surgery e.g. a gastric band. Referral rates differ considerably around the country but the argument for this approach is that a significant weight loss could prevent T2D and that with diabetes being responsible for 10% or all NHS spending this could be a cost-effective intervention.¹⁶

Aiming to increase Beth’s activity levels was potentially a greater challenge. She admitted that she spent most of her days sitting at a desk, in meetings, on a train or in the car. With an early morning start and a late night finish she simply could not see how she could make time for exercise. The Department of Health recommends that people should take at least 30 minutes of activity 5 times a week, and 45-60 minutes for those who need to lose weight,17 but Beth felt this was simply unachievable. She did not enjoy being physically active and her weight made exercise uncomfortable. She could not think of any physical activity that she enjoyed. The practice nurse suggested that she start off by simply using a pedometer to measure the number of steps walked each day over a week. Beth was not surprised to discover that she rarely reached more than 3,500 steps per day, as opposed to the 10,000 steps advised by NHS Choices.¹⁸ She did notice, however, that she did more at the weekends and decided to try to hit a target of 7,500 on Saturdays and Sundays. Once she had achieved this, she increased it to 10,000 and over a period of months she managed to achieve this on 2-3 weekdays too – a vast improvement on her previous activity levels. As she became more active and saw the improvements in her weight and fitness she invested in a bicycle and started to cycle at the weekends too. Small increases in her activity levels had led to much bigger increases over a period of months and these new habits were much more likely to be sustainable in the long run. Research has shown a direct relationship between physical activity levels and insulin sensitivity.¹⁹ The practice nurse had explained the concept of insulin resistance and the link with impaired fasting glycaemia and T2D and this had provided Beth with further motivation to continue with her endeavours.

The Diabetes Prevention Program confirmed that this lifestyle approach to weight loss and increased activity levels was the best way in which to reduce the risk of developing T2D.²⁰ However, the same study also tested the use of metformin as a way of slowing or stopping the progression from impaired glucose tolerance to T2D and this option could have been offered to Beth. It is worth remembering, however, that although the use of metformin to prevent diabetes is endorsed by NICE,1 it is not actually licensed for use in this way. When using a drug off-licence, the patient must be informed and give permission and this should be documented in their records. Beth decided that she was happy to avoid any medication at this stage.

In summary, then, Beth was at increased risk of both diabetes and cardiovascular disease as she had evidence of both impaired glucose tolerance and metabolic syndrome, in spite of her Qrisk score being below 10%. After discovering her QDiabetes score, however, she was encouraged to implement lifestyle changes in order to improve future outcomes and reduce her risk. The support of her practice nurse was invaluable in this respect. The implementation of the NHS Health Checks programme has been patchy across the country but the remit of the NICE Prevention of Diabetes guidelines was to identify and assist people who are at high risk and the importance of continuing this work is further endorsed in the NHS Five Year Forward plan.²¹ Practice nurses need to be aware of the potential to save NHS money and resources by helping people to live healthier, more active lives with less risk of life limiting conditions such as T2D and cardiovascular disease in the future.

REFERENCES

1. NICE PH 38. Prevention of Type 2 Diabetes, 2012 https://www.nice.org.uk/guidance/ph38

2. Hippesley-Cox J et al. Qrisk 2 risk assessment engine BMJ 2008;336:a332

3. Qrisk 2 assessment tool, 2015. http://www.qrisk.org/index.php

4. Rahman M, Simmons RK, Harding A-H, et al. A simple risk score identifies individuals at high risk of developing Type 2 diabetes: a prospective cohort study. Family Practice 2008;25: 191–196.

5. Gray LJ, Davies MJ, Hiles S, et al. Detection of Impaired Glucose Regulation and/or Type 2 Diabetes Mellitus, using primary care electronic data, in a multi-ethnic UK community setting. Diabetologia 2012;55(4):959-66.

6. Hippesley-Cox J, et al. Predicting risk of type 2 diabetes in England and Wales: prospective derivation and validation of QDScore BMJ 2009;338:b880

7. QDiabetes 2014 assessment tool available from http://www.qdscore.org/index.php

8. International Diabetes Federation.The IDF Consensus worldwide definition of the metabolic syndrome, 2014 http://www.idf.org/webdata/docs/IDF_Meta_def_final.pdf

9. Stern M, Williams K, Gonzalez-Villalpando C et al. Does the metabolic syndrome improve identifi cation of individuals at risk of type 2 diabetes and/or cardiovascular disease? Diabetes Care 2004;27(11):2676-81

10. Public Health England. Adult obesity and type 2 diabetes, 2014 https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/338934/Adult_obesity_and_type_2_diabetes_.pdf

11. Te Morenga L, Mallard S, Mann J. Dietary sugars and body weight: systematic review and meta-analyses of randomised controlled trials and cohort studies. BMJ 2013;346:e7492. doi: 10.1136/bmj.e7492.

12. Sacks FM, Bray GA, Carey VJ, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med 2009; 360:859-73.

13. Mattson MP, Wan R (2005) Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems Journal of Nutritional Biochemistry 2005;16(3):129-137

14. Lean M et al. Feasibility and indicative results from a 12 month low energy liquid diet treatment and maintenance programme for severe obesity Brit J Gen Pract 2013; 63:e115-24

15. NICE. Obesity: identification, assessment and management of overweight and obesity in children, young people and adults, 2014 http://www.nice.org.uk/guidance/CG189

16. Diabetes UK. State of the Nation report, 2015 http://www.diabetes.org.uk/Documents/About%20Us/What%20we%20say/State%20of%20the%20nation%202014.pdf

17. Department of Health. UK physical activity guidelines, 2011 https://www.gov.uk/government/publications/uk-physical-activity-guidelines

18. NHS Choices. The 10,000 steps challenge, 2013 http://www.nhs.uk/Livewell/loseweight/Pages/10000stepschallenge.aspx

19. Balkau B et al. Physical Activity and Insulin Sensitivity. Diabetes 2008; 57(10):2613–2618.

20. Diabetes Prevention Program Research Group. Reduction in the Incidence of Type 2 Diabetes with Lifestyle Intervention or Metformin N Engl J Med 2002;346:393-403

21. NHS England. Five year forward view, 2014 http://www.england.nhs.uk/wp-content/uploads/2014/10/5yfv-web.pdf