Optometrists have progressively moved off the sidelines and onto the frontlines of managing patients with diabetes over the past several decades. With optometry’s ever-expanding role in health care, the OD’s role in caring for these patients only begins with the diagnosis of diabetic retinopathy.
Unfortunately, many patients with prediabetes or type 2 diabetes believe they have an irreversible hereditary condition. While this may be the case for those with type 1 diabetes, a different scenario exists for those with type 2 diabetes.
This article will discuss 5 evidence-based lifestyle interventions that ODs can use in managing their type 2 diabetic (and prediabetic) patients, helping to overcome potential long-term diabetic ocular and systemic complications. The interventions mentioned here are not intended to replace standard of care therapy; however, they can prevent the onset and slow progression of diabetic retinopathy. Additionally, they provide a supplemental benefit to the various breakthrough treatments we’ve seen for diabetic retinopathy over the past decade.
Prevalence and Cost
More than 34 million adults in the United States have diabetes, of which seven million are undiagnosed, according to the CDC. This number has almost doubled in the last 20 years, with 95% of cases being type 2 diabetes. Optometrists alone diagnose type 2 diabetes in more than a quarter-million patients per year based on eye exams. Factoring in that one in three adults has prediabetes, nearly half of the US adult population is at risk for sight-threatening retinopathy as well as increased risk of death, primarily due to cardiovascular disease associated with diabetes.
Diabetic retinopathy is the leading cause of vision loss among US adults. Roughly one in three patients with diabetes have some form of DR. It is expected that this will increase to 40% by the year 2050. Presently, there are up to 24,000 new cases of DR each year.
The US healthcare system spends $327 billion to manage diabetes, its complications and the resulting loss in productivity annually. Healthcare costs for patients with diabetes tend to be at least double those of unaffected patients. No amount of healthcare policy reform can sustain this growing economic burden indefinitely.
This is a healthcare crisis. All healthcare professionals interacting with patients with type 2 diabetes, prediabetes and metabolic syndrome must be involved. It is no longer only responsibility of the primary care provider (PCP) or dietician to discuss the importance of lifestyle intervention.
Open the door/Start somewhere
Many patients attend an eye exam expecting a few flashing lights and a glasses prescription. They may not expect to discuss the challenges of managing their diabetes nor health and lifestyle tips to help them better manage it. Sometimes hearing something at the right time or in a slightly different way can be the encouragement someone needs to make change. Try to meet patients where they are when discussing lifestyle interventions. Your goal is to break your recommendations down in a way that is manageable for the particular patient, allowing the patient to engage in and benefit from the conversation. Asking open-ended questions can be a non-threatening way to open the conversation. Asking about last A1c or lab results (or directly referring to it if you have access) can be another way to address the topic. This often leaves room for the patient to mention changes, either positive or negative, in recent months and see how this impacts their blood sugar levels. Printed resources for the patients to take with them after your conversation also gives the patient time to reflect on their own as well as seek out additional information.
Those who are more motivated to make dietary and lifestyle changes will likely respond more proactively and positively to discussion. It's easy for patients to feel uncomfortable by this topic as they’ve often been struggling with diabetes for many years. They may even be frustrated with conflicting information or slow results which makes them feel their efforts are in vain. Encourage them to stick with it and put in the work now to avoid the potentially sight and life threatening repercussions of uncontrolled diabetes.
Start with trying to identify one area for the patient to focus on and provide tangible steps for them to work toward. Goals must be concrete. Work with the patient to identify habits that will be feasible for them to carry out.
Additionally, it can be useful to suggest patients keep a journal of fasted and postprandial blood sugars so they can see tangibly what works for them (and what doesn't). It can be eye opening to see how many patients with diabetes truly don't know what foods and lifestyle habits support optimal blood sugar levels. This can help those who feel overwhelmed or unsure of where to start in making lifestyle changes. Patients must also understand that their diabetic retinopathy took a long time to develop and that resolution will not happen overnight.
When patients are making changes, some really appreciate periodic phone check-ins to recap previous conversations and provide continued encouragement. This will also enhance your rapport with your patients.
Remind patients to work with their PCP whenever making dietary or lifestyle changes as their medications, especially insulin, may need to be modified.
Nix the sugar
The first main topic to address is excessive sugar consumption, including fructose and artificial sweeteners. For example, in 1822 the average consumption of added sugar in the American diet was the equivalent of one 12oz can of soda every five days. In 2020, the average American consumes this amount of added sugar every seven hours. It cannot be assumed that patients have already addressed excess sugar consumption when managing their diabetes. Patients may assume that their medication is sufficient for controlling their disease and not realize the significant improvement to their diabetes and overall health but cutting out sugars.
Excess fructose consumption is directly associated with elevated fasting blood glucose levels, hyperinsulinemia, metabolic syndrome and cardiovascular disease. Fructose from fruit as well as the sweetener high fructose corn syrup is often forgotten by those trying to make healthy dietary changes. Average fructose consumption in the US exceeds 50g per day and is often even higher in adolescents. If you're examining a teenager whether or not they or their family members have diabetes, it can still be a beneficial conversation piece to address this knowing their demographic tends to consume large amounts of this addictive substance which can lead to poorer health outcomes over time. Limiting daily fructose to 20g per day (roughly 1.5 apples) and avoiding products containing high-fructose corn syrup are excellent starting points for those with metabolic problems, including type 2 diabetes.
Over 100 years ago in the pre-insulin days, intermittent fasting and time-restricted eating (TRE) were standard practices used by doctors to optimize health and longevity for their patients with diabetes. Research now shows that TRE remains an effective adjunct therapy for controlling blood glucose levels in type 2 diabetes (and also in those without T2DM).
TRE has a number of beneficial effects including optimizing insulin resistance, fasting blood glucose level, body composition and circadian rhythm. The American Heart Association even advocates TRE to improve cardiovascular health, specifically as it improves specific cardiovascular biomarkers such as total cholesterol, triglycerides, blood pressure and high sensitivity C-reactive protein (hs-CRP).
One study showed that only one in 10 adults regularly maintains a 12-hour fasting window daily. The average daily feeding window (the time between first bite of food and last in the course of a day) exceeds 15 hours. With TRE, meal-timing is limited to an eight- to 120hour window. Essentially, daily caloric intake remains the same but breakfast is eaten later and dinner eaten earlier. TRE works on the principle that we are most insulin sensitive earlier in the day. Leaving longer periods of time throughout the day when not eating allows the body to use the insulin that it creates.
Timing meals within a 10-hour window (leaving 14 hours fasting overnight) was found to have the most favorable outcomes on many cardiometabolic markers in a 12 week study on TRE in patients with metabolic syndrome. The markers included improved insulin resistance, body mass index, low density lipoprotein cholesterol and blood pressure. Additionally Hemoglobin A1c reduced by almost 1 point and liver enzymes, commonly elevated in non-alcholic fatty liver disease, were reduced by roughly 10%. Diet quality and physical activity were not changed in this study. No adverse events were reported.
TRE may be the simplest lifestyle intervention for many patients to make as it does not require learning and adhering to a new diet. This allows patients the freedom to change not what they eat, but simply when. Of course, this can also be combined with dietary and lifestyle adjustments for added beneficial health outcomes.
Low carb craze
You may encounter the most resistance with this one, but it is a topic that cannot be ignored. While the literature on dietary interventions in type 2 diabetes is vast and sometimes conflicting, however studies seem to consistently show a direct relationship between carbohydrate restriction (<45% total calories/day) and improvements in insulin resistance and A1c. Reducing carbohydrates can also improve total cholesterol, triglycerides, blood pressure, hs-CRP. Many apps, such as “MyFitnessPal” can be useful tools to help understand daily caloric and macronutrient intake.
There are many diets that advocate for lower carb consumption including paleo, whole30 and ketogenic. One of the most studied low carb diets is the Mediterranean diet. The Mediterranean diet is lower in carbs and higher in healthy fats. Studies of the Mediterranean diet have consistently shown improvements in glycemic control, weight loss, HbA1c and other cardiovascular risk factors. It has also been shown to be more effective than both low-fat and vegetarian diets for type 2 diabetes.
Low carb diet combined with telemedicine is the approach Virta Health is using to help reach their goal of reversing 100 million cases of type 2 diabetes by 2025. The results of their recent two-year clinical trial reported a 7% remission rate in patients with type 2 diabetes and an average A1c reduction of 0.9% overall. Compared with current standard of care (medication alone) where less than 2% of patients achieve remission, this has promising implications. By contrast, one in three patients with type 2 diabetes who undergo bariatric surgery reach long-term remission.
Quality sleep is an often overlooked aspect of metabolic health. It has been shown that the ideal amount of sleep is seven to eight hours per night for those wanting to manage type 2 diabetes as well as overall health. There is an increased risk of developing or worsening diabetes with sleep times outside of this range.
Asking patients how they sleep can open the door to discuss potential underlying issues such as sleep apnea and blue-light exposure at night (both which also have their own ocular implications). Sleep apnea specifically is a comorbidity in metabolic syndrome, diabetes, and glaucoma, so referring for a sleep study in patients who may be at risk can have a significant impact on the patient's overall health. Explaining that blue light is linked with circadian disruption and melatonin suppression opens the door to a conversation about blue-blocking lens technologies or apps for use before bed if screentime is unavoidable.
This discussion would be remiss without addressing the value of regular movement and exercise. Patients may feel discouraged or overwhelmed to think of starting a new fitness routine. It is important to stress that even basic movement, like walking 20 minutes per day, can significantly improve a patient's metabolic health. Consistency matters more than the intensity of exertion; it's more effective to walk every day at a moderate pace than sprint once a week.
Many patients with diabetes often have other health concerns such as arthritis or obesity that make prolonged periods of weight-bearing exercise difficult. Non-weight bearing exercises such as swimming, aqua aerobics, and stationary cycling are alternatives. Be sure to remind patients that whatever they enjoy doing to stay active will likely be the most sustainable routine for them moving forward. You may encourage patients to see if they might be eligible for a discounted or free gym membership through their medical insurance or through local grants. Knowing options in your community can benefit patients who may face a financial barrier to equipment that could help them move more.
Optometrists are integral members of the healthcare team and are encountering more patients with uncontrolled, and often undiagnosed, metabolic disease such as type 2 diabetes on a daily basis. No longer is it permissible to assume a patient's other healthcare providers are fully addressing lifestyle factors as it relates to diabetes management. It is essential that optometrists discuss the importance of evidence-based lifestyle changes in managing the patient’s overall health. By educating patients on the risk of permanent vision loss from diabetes and guiding them in the necessary lifestyle modifications, the OD can help them decrease the risk, or altogether avoid the long-term ocular and systemic complications associated with diabetes.