It has long been understood that those with type 2 diabetes can find weight loss harder than those without (Norris et al, 2005), and that some interventions to tighten glycaemic control may be to the detriment of weight (Lau and Teoh, 2013). To meet the rising duality of type 2 diabetes with obesity (Gonzalez et al, 2009), in the past few years, diabesity-specific services have become demonstrably effective (Rajeswaran et al, 2012). However, these multi-disciplinary services are not yet available across the UK, and many localities continue to run community-based weight management services as an accessible form of support for people with diabesity.
The comorbidity of diabetes with obesity would classify someone as having “complex” obesity, commonly seen as appropriate for treatment at tier 3 level within a weight management service (NHS England, 2014). Tier 3 weight management is defined as a clinician-led, multi-disciplinary team-approach service aimed at the obese for whom tier 2 services have not been effective (NHS England, 2014). In the absence of specialist diabesity services, is a local tier 3 service able to provide effective support for people with obesity and type 2 diabetes?
As part of an MSc project, a retrospective review of a tier 3 weight management service was conducted to compare outcomes of those with and without a diagnosis of type 2 diabetes.
Warrington and Halton Hospitals NHS Trust offers a community-based, specialist weight management tier 3 service for the Halton locality. Halton is in Cheshire in the north-west of England and the overall health of people in Halton is generally worse than the England average, with an adult and child obesity rate 12–15% higher than the national average (Public Health England, 2014). In 2012/2013 there were 7367 people recorded with a diagnosis of diabetes in the Halton locality (including type 1 or type 2 diabetes). This equates to a prevalence of 7.2% (Public Health England, 2014), which is higher than the national average of 6%. Nationally, 90% of diabetes diagnoses are for type 2 diabetes (NHS Choices, 2012), which would approximate to a local type 2 diabetes population in Halton of around 6600 people. Therefore, weight management services play an important role in this area.
The service provided in Halton is available to people with obesity and diabesity and is dietetic-led. Entry to the tier 3 service is through referral from a healthcare professional, although individuals can also self-refer into the tier 2 service and be appropriately triaged for complex support. Patients enrolled are able to receive support for up to 2 years during weight loss and then during the maintenance phases. In addition, those seeking bariatric surgery are able to prepare via this service.
After referral, individuals are formally assessed at their initial appointment (45 minutes), and then again at 6, 12, 18 and 24 months (30-minute appointments). Individuals referred to the tier 3 service primarily receive dietitian support. However, they may also choose to receive additional sessions with a dedicated cognitive behavioural therapist providing psychological input, and they have the option of accessing tier 2 activities, such as healthy eating education and physical activity. Users of the service are also able to access email and telephone support between appointments to suit their individual needs. Dietary strategies may include tailored portion plans, meal replacement plans, pharmacotherapy or SMART-goal stepwise changes towards a healthier lifestyle.
Aim and analysis
The aim of the analysis was to determine whether community-based, tier 3 weight management services are able to provide as effective support for people with a diagnosis of type 2 diabetes as they do for people without.
A 6-month study period was selected because it represents a typical time-frame for weight loss before plateauing is likely to occur (NICE, 2006). The effect of glucose-lowering therapy was also investigated in the type 2 diabetes group. BMI and weight at baseline and at 6 months for the type 2 diabetes group and the non-type 2 diabetes group were analysed in a two-way related sample design. Paired t-tests were used analyse data sets and statistical significance was delimited at P<0.05 and exact P values are cited.
In total, 231 adults over the age of 18 years were referred to receive tier 3 support between 1 June 2013 and 31 December 2013 (Figure 1). Of the 168 people who went on to receive input, 78.5% were female and 21.5% male. The age of participants was not recorded or evaluated within the scope of this review.
After 6 months, 73 people were continuing to receive input; 18 people were diagnosed with type 2 diabetes and 55 people were not (see Table 1 for analysis). The baseline BMI was not significantly different between the type 2 diabetes group and the non-type 2 diabetes group (42.97 kg/m2 and 41.31 kg/m2 respectively [P=0.888]). Baseline weight was also not significantly different. After 6 months, both the diabetes and the non-diabetes group achieved a significant weight loss (P=0.007 and P=0.0001 respectively). The diabetes group lost a median of 4.26 kg, and in the non-type 2 diabetes group lost a median of 3.76 kg. The difference between the two groups was again not significantly different (P=0.582). The BMI change was also not significantly different between the two groups (P=0.683).
Attrition was observed in this study: 24.2% of participants did not accept the referral into the service, and a further 41.1% (n=95) dropped out of the intervention before 6 months. The rate of attrition was similar between those with and without a diagnosis of type 2 diabetes. Approximately 55% of both groups did not complete the 6-month study period.
Effect of pharmacological treatment
After 6 months, the type 2 diabetes group consisted of 18 people. As a result, this limited the statistical analysis that could be conducted on the effect of the pharmacological treatment in the type 2 diabetes group. However, mean weight loss was calculated for the broad pharmacological sub-groups for observational discussion (see Table 2).
The results of the study show that this tier 3 service supports weight loss equally effectively in those with and without a diagnosis of type 2 diabetes. Overall, the weight losses observed here compare with similar services in the UK. An NHS-funded programme in Shropshire evaluated weight loss in 1129 participants, and found that men and women lost a mean of 5.7 kg and 4.2 kg respectively over 12 weeks (Bhogal and Langford, 2014), and the specialist diabesity clinic at the Mid Yorkshire NHS Trust found that 143 people enrolled in a 12-week programme had a mean weight loss of 3.6% 3 months after completion (Srinivasan, 2014).
In this study, over three-quarters of the enrolled participants were women. The gender imbalance of enrolled participants observed in this case study has been observed elsewhere. The Shropshire study also reported that 78.5% of the participants were female (Bhogal and Langford, 2014), and a NHS-based tier 3 programme in Glasgow found 73.7% of starting participants were female (Morrison et al, 2011). This trend has also been observed in weight management services for US-military veterans; Spring et al (2014) reported that although only 5.5% of veterans are female, 14% of the 18865 weight management participants were female.
Men tend to be under-represented in weight loss trials, as well as in interventions. This could be due to the perception that they are under less cultural pressure to lose weight, or that they perceive themselves as less overweight than female counterparts, resulting in lower motivation to lose weight. Men may also be less likely to seek external help (Pagato et al, 2012).
More than half of the originally enrolled individuals did not complete the 6-month service, either declining the offer of referral or ending their attendance of the service. Attrition is commonly seen in weight management services and is reported in the Glasgow, Shropshire and US veterans programmes discussed above (Morrison et al, 2011; Bhogal and Langford, 2014; Spring et al, 2014 respectively).
Although what constitutes as “attrition” is not well defined, lower starting BMI and younger age (Gill et al, 2011), depressive symptoms, and seeing low weight loss during the first few weeks of treatment (Fabricatore et al, 2009) have been associated with increased attrition. In terms of service provision, the US veterans weight loss programme, which was held over multiple sites and, therefore, offered slightly different strategies, found that retention rates were increased in localities offering programmed physical activity, structured low-calorie plans and a rewards system (Spring et al, 2014).
People with chronic conditions are also more likely to fail to attend therapeutic services. Especially with diabetes, a lack of perception of the severity of the condition and not having developed complications can be a factor in non-attending services. High HbA1c, high BMI and high blood pressure were also linked with lower attendance (Paterson et al, 2010). Paterson et al (2010) also note that where symptoms do not cause pain or discomfort, patients may be less motivated to attend appointments. Making multiple health behaviour changes simultaneously has also been observed to be less effective in causing change than implementing stand-alone changes (Wing et al, 2001), although some combinations may act synergistically to improve outcome.
This may be where the value of specialised diabesity services have the edge: the capacity for professionals to work closely together with the patient to establish priorities, rather than each discipline making demands of the patient to achieve goals. Priorities such as encouraging regular blood glucose testing, or even taking medication on a regular basis, could be more imminently important than diet and lifestyle changes when examined holistically.
Representing the local diabetes population
Given the prevalence of type 2 diabetes in the Halton area, it seems likely that the small number of referrals to the service of people with type 2 diabetes represents only a tiny proportion of those in the locality who are diabese and looking for support. Other forms of support are of course available for those who wish to prioritise dietary change and weight loss: for example, weekly weight checks at local GP practices, commercial slimming groups and structured education groups. It is not known whether patients are given the options of support by the relevant clinician, or whether all relevant clinicians are aware of the different services available locally.
Impact of anti-diabetes pharmacotherapy
Although a larger cohort is needed to add statistical weight to the observations, Table 2 suggests that weight loss may be more successful in those not using insulin. Insulin is well known to induce considerable weight gain (Lau and Teoh, 2013). According to NICE treatment guidelines (2009), insulin is usually initiated after a combination of other glucose-lowering agents have failed to provide adequate control; therefore, it tends to be instigated in people whose type 2 diabetes has progressed significantly. If individuals with diabesity have not received weight loss support during the early stages of disease progression, further weight gain is likely to occur once the commencement of insulin, or indeed other anti-diabetes medication, is required (Lau and Teoh, 2013).
Previous studies have demonstrated the positive impact of dietary intervention within the first year of diabetes diagnosis – stimulating weight loss, improved HbA1c and fewer increases in anti-diabetes medication agents compared with standard care (Andrews et al, 2011). It is already currently recommended that people with type 2 diabetes receive structured education, preferably within a group setting around the time of diagnosis, and followed up annually (National Collaborating Centre for Chronic Conditions, 2008). As discussed above, individuals who are receiving structured education may not feel able to take on the additional commitment of regular appointment attendance and lifestyle changes – be that with a weight management service or a specialist diabesity clinic. This leaves the referring clinician to decide with the individual patient what their priorities are and their ability to focus on achieving them: are they more likely to respond to a structured approach, to diabetes education, or would tailored dietary intervention in the first instance be more appropriate?
Preventing type 2 diabetes and impaired glucose regulation
It has been outside the scope of this case study to consider the role of this service for those at risk of developing type 2 diabetes. Given that nationally one in 70 adults is estimated to have undiagnosed type 2 diabetes (Diabetes UK, 2012), it is also likely that a significant number have impaired glucose regulation without a diabetes diagnosis, possibly including those seeking support from this service.
Improvements to the service
Measuring, and identifying changes in, HbA1c is not routinely conducted within the service in Halton. It is well-evidenced that weight loss generally improves diabetes control (Lau and Teoh, 2013), underpinning guidance encouraging individuals with type 2 diabetes to engage with lifestyle changes (NICE, 2009; 2014). Incorporating HbA1c testing (alongside other markers such as lipid profile and blood pressure) as part of the service would enable evaluation of the service on secondary outcomes such as glycaemic control and cardiovascular risk.
A tier 3 weight management service can be as effective at assisting people with a type 2 diabetes diagnosis to lose weight as it is for people without a diabetes diagnosis. Where this type of provision exists, it contributes positively to the range of services available for individuals to improve their diet and lifestyle. However, responsibilities lie with the clinician in encouraging self-management and guiding them into appropriate treatment options.