Abstract

Not much has been reported about Idiopathic Postprandial syndrome, especially in Africa. Many cases are often wrongly diagnosed as reactive hypoglycemia. Idiopathic postprandial syndrome refers to signs and symptoms of hypoglycemia in the absence of low blood sugar occurring after meals and is of unknown cause. We report a case of Idiopathic Postprandial Syndrome in a 44-year old woman living in Nigeria. We present a 44-year-old woman who has been having recurrent hypoglycemic symptoms, which include dizziness, body weakness, lightheadedness, restlessness, headaches, and fatigue after she eats a meal (Post-prandial) for a year. Blood glucose is normal during episodes, and extensive examinations and investigations yielded no other cause. Idiopathic postprandial syndrome (IPS) is a condition in which an individual experiences symptoms of hypoglycemia without having biochemical evidence. The major difference between idiopathic postprandial syndrome (IPS) and hypoglycemia is that IPS may present with only symptoms of low blood sugar without the other components of Whipple’s triad. These symptoms usually occur within a few hours of eating and the exact cause is not known. Managing the possible identified triggers, dietary modification and the use of alpha-glucosidase inhibitors have been seen to improve the condition. Much work still needs to be done to identify the exact etiology of the syndrome.

1. Introduction

Hypoglycemia is described as blood sugar of less than 3.0mmol/L in normal individuals and 3.9mmol/L in diabetic patients; this is often accompanied by adrenergic symptoms which resolve on ingestion of glucose meals ¹. The term idiopathic postprandial syndrome refers to signs and symptoms of hypoglycemia in the absence of low blood sugar occurring after meals and is of unknown cause ².

Kosuda et al. ³ evaluated patients with postprandial symptoms, and it was seen that some had blood glucose within the normal reference range despite the presence of signs and symptoms seen in hypoglycemia. Ivan et al. ⁴ also demonstrated adrenergic symptoms in some patients following oral glucose ingestion despite the normal blood glucose levels.

Charles et al. ² studied the relationship between idiopathic postprandial hypoglycemia and glucose homeostasis. However, the study could not identify abnormalities of glucose homeostasis which could have explained the hypoglycemic-like signs and symptoms the patients experienced. They concluded that this disorder should be termed idiopathic postprandial disorder to avoid the wrong label of “chemical hypoglycemia” since the blood glucose readings were normal ².

Some of these patients with symptoms of hypoglycemia, despite normal blood glucose readings, are often wrongly labeled as reactive or postprandial hypoglycemia, hence the need for further study on this clinical problem. This will encourage the use of the terminology “idiopathic postprandial syndrome”. It describes the timing of the event without the wrong nomenclature of “hypoglycemia”.

In this paper, we present a case of a middle-aged woman with the idiopathic postprandial syndrome. To the best knowledge of the authors, no such peer-reviewed case has ever been reported from Africa, hence the need for this report.

2. Case Presentation

The index patient is a 44-year-old woman who has been having recurrent hypoglycemic symptoms, which include dizziness, body weakness, lightheadedness, restlessness, headaches, and fatigue after she eats a meal (Post-prandial). This has been going on for a year. There was no known incident that happened prior, and she is not a known diabetic. She is not on any regular medications nor does she use any anti-diabetic medications. She has no symptoms of liver or renal failure. She does not drink alcohol or smoke. Her dietary habits, before diagnosis, varied between staple foods and processed meals.

On examination, she was afebrile, not cyanosed, not dehydrated, did not have pedal edema nor did she have generalized lymphadenopathy. She experienced increased heart rate values which ranged between 100bpm and 130 bpm after meals. All other examination findings were normal.

The initial working assessment was reactive hypoglycemia. Baseline investigations which included a Full Blood Count and Monitored blood sugar levels after meals at 30 minutes intervals were carried out. The Full blood count was essentially normal, and the blood sugar measurements taken at 30 minutes intervals up to 3 hours showed consistent values between 5mmol/l and 8 mmol/l despite the occurrence of these hypoglycemic symptoms. All parameters in the Electrolytes, Urea, and Creatinine test as well as the Liver Function Tests were equally within normal limits.

Further investigations were carried out to assess the possible cause of this phenomenon. She had a fasting insulin test done to check for any abnormality. As can be seen in Figure 1, the insulin level was normal. She had a serum amylase and lipase done which yielded normal results. (Amylase- 79 U/L, Lipase 62 U/L). Results in Figure 2. She also had a Computed Tomography scan of the abdomen to exclude any intra-abdominal lesion, however, the results were normal.

A final diagnosis of the idiopathic postprandial syndrome was made. She was placed on an Alpha-glucosidase inhibitor and was counseled on the need to eat a high-fiber diet. She was followed up in a month and she reported a mild improvement.

3. Discussion

Hypoglycemia is diagnosed by Whipple’s triad which is made up of low plasma glucose level, symptoms of hypoglycemia, and symptomatic relief with correction of the hypoglycemia ¹. While several factors can be responsible for symptoms of hypoglycemia, idiopathic postprandial syndrome is not a common cause. In most situations, hypoglycemia can be seen to be in a fasting state or in diabetic patients where it is usually attributed to the drugs used in diabetes control.

Idiopathic postprandial syndrome (IPS) is a condition in which an individual experiences symptoms of hypoglycemia without having biochemical evidence. Hence, the patient may experience hypoglycemic symptoms such as shakiness, irritability, palpitations, pallor, hunger, anxiety, confusion, etc. IPS does not lead to very serious immediate and long-term complications such as seizures, coma, and brain damage. The blood glucose may be within normal range and administration of glucose may not cause an improvement in the symptoms. The major difference between idiopathic postprandial syndrome (IPS) and hypoglycemia is that IPS may present with only symptoms of low blood sugar without the other components of Whipple’s triad ⁵

These symptoms usually occur within a few hours of eating and the exact cause is not known. However, possible triggers identified so far with ongoing research include eating heavy carbohydrate meals, excessive consumption of alcohol, exogenous insulin production, excessive catecholamine release in stressful conditions, blood glucose levels being in lower limits of the normal range, renal diseases, rapid dropping of blood glucose levels from higher limits to lower limits of the normal range, etc. ⁶

The index patient had hypoglycemic features highlighted earlier but finding the cause proved difficult. Given that she was not diabetic or on any hypoglycemia-inducing medication, that ruled out such cause of her symptoms. Other possible causes such as alcohol ingestion and stressful events were ruled out. Furthermore, radiological studies of the abdomen didn’t give findings suggestive of an insulinoma, nor did the serum insulin. The amylase, and lipase levels, as well as liver, kidney, and thyroid function tests, were within the normal range.

The treatment for IPS entails identifying possible triggers and managing them. These could include dietary modification such as reducing the number of meals taken per time while increasing frequency and taking foods rich in fiber and less in glycemic index such as lean proteins. Other measures include cutting down on alcohol consumption and refined carbohydrates intake. A further step above lifestyle modification includes the use of medications such as alpha-glucosidase inhibitors ⁷. In the index patient dietary modification was advised. She was also commenced on the above-named medication after which some improvement was seen.

4. Conclusion

The recognition of postprandial syndrome is very important as this would enable clarity for both the physician and the patient. It can be argued to be a diagnosis of exclusion, like in the case of this index patient. More work needs to be done to shed more light on the etiology of Idiopathic Postprandial Syndrome as well as to elucidate more effective treatments.

Acknowledgements

There was no funding for this paper. Consent was taken from the patient before the writing of this paper.

References