A 44-Year-Old Woman With Type 1 Diabetes and a Recent History of Diabetes "Out of Control"

K.P. is a 44-year-old woman who was diagnosed with type 1 diabetes 22 years ago. She has been diagnosed with background retinopathy, which has been stable, and microalbuminuria, which is well-controlled on an angiotensin-converting enzyme (ACE) inhibitor. She has hypercholesterolemia, which is controlled with simvastatin (Zocor), and neuropathy. She has no history of hypertension, tobacco abuse, or cardiovascular disease.

She currently is treated with ultralente insulin and a rapid-acting insulin in boluses before each meal. She has had good control, as determined by HbA_1c levels averaging 7% over the past 2 years. Recently, however her HbA_1c increased to 9%.

K.P. is 5′ 3′′ tall, and her weight has recently decreased unintentionally from 115 to 110 lb. She works as a special education teacher and drives daily between two schools.

One week ago, she was found to be disoriented and hypoglycemic after her car ran into a curb while she was driving. Her blood glucose level was 26 mg/dl as measured by the paramedics who were called to the scene. After treatment, she stated that she had eaten lunch 2 h before the accident and that her blood glucose before lunch had been 130 mg/dl. She had taken her normal rapid-acting insulin bolus and had no exercise that day or the day before. Her carbohydrate intake for lunch and the amount of rapid-acting insulin that she injected seemed appropriate (1 unit for every 15 g carbohydrate). She was referred to a dietitian certified in diabetes education for evaluation.

1. What is causing K.P.'s postprandial hypoglycemia?

2. Why has her diabetes been so difficult to control recently, with unexpectedly high and low blood glucose levels after meals?

3. What is the cause of her unintentional weight loss?

The dietitian asked K.P. to fill out a questionnaire at the beginning of her visit. She indicated the following:

• Do you feel full before you've eaten much? Yes.

• Have you had any changes in appetite recently? Yes.

• Have you gained or lost weight recently? Yes.

• Do you have any unexplained trouble controlling your blood sugars? Yes.

• Do you have any of the following symptoms: bloating, heartburn, abdominal cramping? Yes.

• Do you have unexplained nausea? Yes.

• Do you have unexplained vomiting of undigested food, especially in the morning? No.

• Have you had any diarrhea or constipation recently? Is it alternating? No.

K.P. was very upset that she was experiencing blood glucose fluctuations, which did not make any sense to her. The dietitian asked her to keep detailed food, exercise, and self-monitoring of blood glucose (SMBG) records for the next week. (See Figure 1.)

At the next visit, these records were evaluated. They showed low blood glucose levels 1–2 h after meals. The blood glucose levels did not seem to correlate with the expected absorption of nutrients postprandially or with the action of the insulins.

K.P. had some hypoglycemia unawareness, but if she was not very busy, she was able to recognize the subtle cues that she now has with hypoglycemia.

A drug history revealed no use of narcotics, tricyclic antidepressants, or anticholinergics, which might affect stomach motility. Although high-fat meals can cause the same pattern of delayed emptying and later rise in blood glucose, K.P. recorded that she ate low-fat meals. It was suspected that she had diabetic gastroparesis.

The referring physician was consulted and ruled out anemia and celiac disease. He then decided on an empiric trial of a promotility agent and nutrition recommendations as suggested by the dietitian. The nutrition recommendations for mild gastroparesis were as follows:

1. Eat six or more meals/day.

2. Avoid foods high in fat, and avoid adding too much fat to foods.

3. Avoid high-fiber foods.

4. Chew food well.

5. Sit up after meals; don't recline for 1 h following a meal.

6. Walk after meals when possible to enhance stomach emptying.¹ 

In addition, a new insulin regimen was recommended. K.P. was instructed to increase the frequency of her SMBG, decrease her ultralente dose by 10% before bed, and give a divided rapid-acting insulin bolus—half immediately after the meal and half 2 h postprandially. The rapid-acting insulin bolus was calculated for the grams of carbohydrate in each meal, with any correction factors for high blood glucose added. Figure 2 shows K.P.'s post-treatment SMBG records.

Although there is a lack of evidence-based nutrition interventions for gastroparesis in diabetic patients, the following nutritional guidelines may be effective:⁵ 

1. Early satiety is one of the hallmarks of gastroparesis. Because larger volume of foods slow gastric emptying, smaller more frequent meals may help.

2. Liquids usually empty from the stomach more easily and rapidly than solids. Solids require normal functioning of the antrum and fundus for churning, mixing, and exiting. Because patients often report increased fullness as the day proceeds, consuming mostly liquids toward the end of the day may be considered.

3. Fiber, especially pectin, is known to slow stomach emptying. If bezoar formation is a concern, patients should avoid oranges, persimmons, coconuts, berries, green beans, figs, apples, sauerkraut, brussel sprouts, potato peels, and legumes.

4. Fatty foods or foods with a significant amount of fat added to them exit the stomach more slowly and may be poorly tolerated. However, many patients tolerate fat in liquid form, such as milkshakes, whole milk, and nutritional supplements.

Other methods of insulin treatment may be used to help with gastroparesis. Some patients benefit from taking a bolus of half rapid-acting and half regular insulin after meals. For patients on an insulin pump, a dual wave may be used to more closely approximate the rise in blood glucose seen with delayed absorption. For patients who use insulin injections, the rapid-acting insulin or regular insulin given with a meal may be divided, with half given as the patient eats and half given 1–2 h postprandially.

• Gastroparesis develops in 40–50% of patients with longstanding type 1 diabetes and 30–40% of those with longstanding type 2 diabetes.

• Symptoms are often vague and may not be expressed at the clinic visit. Early satiety is one of the hallmarks of gastroparesis. Symptoms such as appetite changes and fluctuations in blood glucose are common.

• Hyperglycemia can cause transient gastroparesis in some patients. Optimal glycemic control is imperative for maximum utilization of nutritional intervention.

• Medical nutrition therapy, patient education, and a change in insulin therapy may give relief.

• Because of the nature of the subject matter discussed (nutrient absorption patterns), dietitians are often the member of the diabetes care team to first suspect a diagnosis of gastroparesis. Dietitians often have the opportunity to discover the presence of gastroparesis in their patients and can be proactive regarding treatment recommendations.