The need for a guideline

Prevention and remission of type 2 diabetes (SIGN)
Healthcare Improvement Scotland
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Type 2 diabetes occurs when the body no longer produces enough insulin to regulate blood glucose levels or has developed resistance to the insulin that is produced. Owing to recent scientific breakthroughs,1,2 type 2 diabetes is no longer seen as a progressive and irreversible disease. We now know that prevention and remission are possible with clinically effective interventions, notably weight loss. This provides a powerful tool to address the rising trajectory of type 2 diabetes incidence and related ill-health in Scotland. Remission of type 2 diabetes is only one aspect; prevention will reduce the number of people in Scotland developing the condition in the first place.

The number of people being diagnosed with type 2 diabetes is increasing every year. Currently, there are almost 300,000 people living in Scotland with type 2 diabetes, with new diagnoses in excess of 20,000 in 2022.3 In England, 12% of the adult population (5.1 million) have prediabetes. If extrapolated to Scotland the estimate is around 500,000.4 The number of people living with type 2 diabetes in Scotland increased by a third between 2011 and 2021.5 Taking into account projected population changes over the next 20 years, Public Health Scotland estimates that the number of people living with diabetes in Scotland will increase by 36% by 2044.5 The average age at which people are diagnosed is also decreasing, and is associated with a poorer prognosis. A diagnosis of type 2 diabetes at age 40 reduces life expectancy by around 10 years, driven by the increased risk of cardiovascular disease (CVD).6

The annual economic cost to Scotland of type 2 diabetes is estimated at £2.37 billion taking into account loss of productivity as a result of impaired health, direct healthcare costs and investment to mitigate the impact of obesity.7 The cost to the NHS in Scotland of diabetes treatment alone is estimated at £1.6 billion (around 10% of total health expenditure).7  

Social determinants of health

Type 2 diabetes does not affect our population equally. In Scotland, people living in the most deprived communities having a 77% greater chance of developing diabetes than those in the most affluent areas. The short-term mortality risk from type 2 diabetes is higher among those living in more deprived areas, with the impact on disability-adjusted life years in these communities also 2.5 times greater.8 Uptake and completion of structured education and weight-management programmes is poorer in the most deprived areas (Scottish Index of Multiple Deprivation (SIMD) areas 1 and 2) despite around 50% of all referrals originating from people living in those areas.9

Many of the factors that drive type 2 diabetes risk cannot be controlled by the individual. These social determinants of health are the social, cultural, political, economic and environmental conditions into which people are born, grow up, live, work and age, and their access to power, decision making, money and resources that shape the conditions of their daily life. The social determinants of health influence a person’s opportunity to be healthy, their risk of illness, health behaviours and healthy life expectancy. Health inequities result from the uneven distribution of these social determinants.10 These have a significant impact on the ability to prevent and manage type 2 diabetes effectively.

 

Social determinants of health
Figure 1: The social determinants of health (adapted by Scottish Government11 from The University of Wisconsin Population Health Institute,12 Booske et al, 201013 and the King’s Fund14

At the individual level, non-modifiable risk factors such as increased age, ethnicity and genetic predisposition contribute to a person’s overall likelihood of developing type 2 diabetes. Even though some people may feel healthy, they can still be at risk of developing the condition.

At the time of type 2 diabetes diagnosis, people from minority ethnic populations in the United Kingdom (UK), particularly those of South Asian ethnicity, are, on average, younger, have a lower body mass index (BMI), and higher HbA1c levels than white or European populations (see Tables 1 and 2).15-24

Table 1: Average age at diagnosis of type 2 diabetes in UK population from retrospective studies15-24

Ethnicity

Mean age range (years)16-21,24

Median age range (years)15, 22

Number of studies

(participants)
White or European 54.6–63.4 65.0–67.0 9 (646,378)
South Asian 46.0–53.0 55.0–67.0 9 (49,811)
Black or African-Caribbean 48.0–55.8 54.0–68.0 8 (22,064)
Chinese 56.7 60 2 (704)
Arab n/a 56 1 (143)

 

Table 2: Mean BMI cut-offs for overweight and classes of obesity in the UK

Ethnicity

BMI cut-off 25kg/m2

(overweight)15

BMI cut-off 30kg/m2

(class 1 obesity)15,22,23

BMI cut-off 35 kg/m2

(class 2 obesity)23
White or European 25.0 30.0 35.0
South Asian 19.2a 23.3–25.2a

Female 25.7b

Male 27.1
Black or African-Caribbean 23.4 25.9–28.1

Female 29.0

Male 39.3
Chinese 22.2 24.6–26.9

Female 27.1

Male 28.3
Arab 22.1 26.6 Not included

 a Indian, Pakistani, Bangladeshi, Nepali, Sri Lankan, and Tamil. b Indian, Pakistani and Bangladeshi.

In Scotland 87% of people with type 2 diabetes are living with overweight or obesity, with 67% of the overall Scottish adult population living with a body mass index (BMI) over 25kg/m2.25 

While healthcare professionals are unable to change the social determinants of health or non-modifiable risk factors, there is an opportunity to support some people to live healthier lives, in ways appropriate to their circumstances, which might include weight loss.

Current provision

Current provision of weight management services for the prevention and treatment of type 2 diabetes differs across NHS boards. This includes variation in the type of programmes that are offered, duration and follow up, healthcare professionals involved in delivery, eligibility and access criteria for those services and where and how the services are delivered. Digitally enabled care of people with diabetes has rapidly increased and this will feature permanently in future delivery models, particularly as the needs of a growing number of people are sought.

This evidence-based guideline has the potential to improve and standardise the approach to identifying people at the highest risk of developing type 2 diabetes and ensure that programmes targeting type 2 diabetes prevention are more likely to be effective. There is also the potential to ensure more equitable access to services for people at high risk of, and living with, type 2 diabetes.

References

  1. 1          Astbury NM, Aveyard P, Nickless A, Hood K, Corfield K, Lowe R, et al. Doctor Referral of Overweight People to Low Energy total diet replacement Treatment (DROPLET): pragmatic randomised controlled trial. BMJ 2018;362:k3760.

    2          Lean MEJ, Leslie WS, Barnes AC, Brosnahan N, Thom G, McCombie L, et al. Primary care-led weight management for remission of type 2 diabetes (DiRECT): an open-label, cluster-randomised trial. Lancet 2018;391(10120):541-51.

    3          Scottish Diabetes Group. Scottish Diabetes Survey 2022. [cited 9 Sep 2024]. Available from url: https://www.diabetesinscotland.org.uk/wp-content/uploads/2023/10/Scottish-Diabetes-Survey-2022.pdf

    4          Office for National Statistics. Risk factors for pre-diabetes and undiagnosed type 2 diabetes in England: 2013 to 2019. [cited 9 Sep 2024]. Available from url: https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/healthinequalities/bulletins/riskfactorsforprediabetesandundiagnosedtype2diabetesinengland/2013to2019

    5          Public Health Scotland. Scottish Burden of Disease: Future prevalence and burden of diabetes. 2024. [cited 10 Sep 24]. Available from url: /www.scotpho.org.uk/media/2422/2024-06-04-scottishburdenofdisease-diabetes.pdf

    6          Emerging Risk Factors Collaboration. Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation. Lancet Diabetes Endocrinol 2023;11(10):731-42.

    7          Diabetes Scotland. State of the Nation 2015: The Age of Diabetes. [cited 10 Sep 2024]. Available from url: https://diabetes-resources-production.s3-eu-west-1.amazonaws.com/diabetes-storage/migration/pdf/SOTN%2520Diabetes.pdf

    8          Unwin N. Socio economic position, the risk of pre and type 2  diabetes, and implications for prevention. Institute of Health and Society, University of Newcastle. [cited 10 Sept 24]. Available from url: https://www.nice.org.uk/guidance/ph35/evidence/ep-3-socioeconomic-status-and-risk-factors-for-type-2-diabetes-pdf-433771165

    9          Public Health Scotland. Referrals to NHS board commissioned weight management services. [cited 10 Sep 24]. Available from url: https://publichealthscotland.scot/publications/referrals-to-nhs-board-commissioned-weight-management-services/referrals-to-nhs-board-commissioned-weight-management-services-1-october-2019-to-30-september-2021/

    10        World Health Organization. Health Promotion Glossary of Terms 2021. [cited 10 Sep 24]. Available from url: https://www.who.int/publications/i/item/9789240038349

    11        Scottish Government. Realistic Medicine - Doing the right thing: Chief Medical Officer annual report 2022 to 2023. [cited 11 Sep 2024]. Available from url: https://www.gov.scot/publications/realistic-medicine-doing-right-thing-cmo-annual-report-2022-2023/pages/4/

    12        The University of  Wisconsin Population Health Institute, County Health Rankings and Roadmaps. 2024 National findings report - creating thriving communities through civic participation. [cited 11 Sep 24]. Available from url: www.countyhealthrankings.org

    13        Booske BC, Athens JK, Kindig DA, Park H, Remington P. Different perspectives for assigning weights to wider determinants of health. [cited 11 Sep 2024]. Available from url: www.countyhealthrankings.org/sites/default/files/differentPerspectivesForAssigningWeightsToDeterminantsOfHealth.pdf

    14        Buck D BA, Dougall D, and Robertson R. A vision for population health: towards a healthier future. [cited 11 Sep 2024]. Available from url: https://www.kingsfund.org.uk/insight-and-analysis/reports/vision-population-health

    15       Caleyachetty R, Barber TM, Mohammed NI, Cappuccio FP, Hardy R, Mathur R, et al. Ethnicity-specific BMI cutoffs for obesity based on type 2 diabetes risk in England: a population-based cohort study. Lancet Diabetes Endocrinol 2021;9(7):419-26.

    16       Iyen B VY, Akyea R, Weng S, Qureshi N, Kai J. Ethnic disparities in mortality among overweight or obese adults with newly diagnosed type 2 diabetes: a population-based cohort study. Journal of Endocrinological Investigation 2022;45(5):1011-20.

    17       Malik MO, Govan L, Petrie JR, Ghouri N, Leese G, Fischbacher C, et al. Ethnicity and risk of cardiovascular disease (CVD): 4.8 year follow-up of patients with type 2 diabetes living in Scotland. Diabetologia 2015;58(4):716-25.

    18       Mathur R, Hull SA, Hodgson S, Finer S. Characterisation of type 2 diabetes subgroups and their association with ethnicity and clinical outcomes: a UK real-world data study using the East London Database. Br J Gen Pract 2022;72(719):e421-e9.

    19       Mathur R, Palla L, Farmer RE, Chaturvedi N, Smeeth L. Ethnic differences in the severity and clinical management of type 2 diabetes at time of diagnosis: A cohort study in the UK Clinical Practice Research Datalink. Diabetes Res Clin Pract 2020;160:108006.

    20       Paul SK, Owusu Adjah ES, Samanta M, Patel K, Bellary S, Hanif W, et al. Comparison of body mass index at diagnosis of diabetes in a multi-ethnic population: A case-control study with matched non-diabetic controls. Diabetes Obes Metab 2017;19(7):1014-23.

    21       Srinivasan S, Liju S, Sathish N, Siddiqui MK, Anjana RM, Pearson ER, et al. Common and Distinct Genetic Architecture of Age at Diagnosis of Diabetes in South Indian and European Populations. Diabetes Care 2023;46(8):1515-23.

    22       Tillin T, Sattar N, Godsland IF, Hughes AD, Chaturvedi N, Forouhi NG. Ethnicity-specific obesity cut-points in the development of Type 2 diabetes - a prospective study including three ethnic groups in the United Kingdom. Diabet Med 2015;32(2):226-34.

    23       Wang S, Shen J, Koh WP, Yuan JM, Gao X, Peng Y, et al. Comparison of race- and ethnicity-specific BMI cutoffs for categorizing obesity severity: a multicountry prospective cohort study. Obesity (Silver Spring) 2024;32(10):1958-66.

    24       Wright AK, Welsh P, Gill JMR, Kontopantelis E, Emsley R, Buchan I, et al. Age-, sex- and ethnicity-related differences in body weight, blood pressure, HbA(1c) and lipid levels at the diagnosis of type 2 diabetes relative to people without diabetes. Diabetologia 2020;63(8):1542-53.

    25        The Scottish Government. Obesity - The Scottish Health Survey 2021. [cited 11 Sep 2024]. Available from url: https://www.gov.scot/publications/scottish-health-survey-2021-volume-1-main-report/pages/10/