If a one-hour spike was high but came down promptly, would you still worry? I'd be inclined to think my body was handling it properly and not be concerned.
Two-hour postprandial testing - I did some research. Sorry if I've already posted this.
Postprandial Blood Glucose
1. American Diabetes Association
* ADA, American Diabetes Association
* CVD, cardiovascular disease
* DCCT, Diabetes Control and Complications Trial
* FPG, fasting plasma glucose
* MPG, mean plasma glucose
* OGTT, oral glucose tolerance test
* PPG, postprandial glucose
* PPGE, postprandial glucose excursion
* UKPDS, U.K. Prospective Diabetes Study
Individuals with diabetes are at increased risk of developing microvascular complications (retinopathy, nephropathy, and neuropathy) and cardiovascular disease (CVD). The Diabetes Control and Complications Trial (DCCT) (1) and U.K. Prospective Diabetes Study (UKPDS) (2) showed that treatment programs resulting in improved glycemic control, as measured by HbA1c, reduced the microvascular complications of diabetes. The effect of these treatment programs on reducing CVD was less clear. However, some epidemiological studies suggest that there may be a relationship between glycemic levels and CVD.
In the management of diabetes, health care providers usually assess glycemic control with fasting plasma glucose (FPG) and premeal glucose measurements, as well as by measuring HbA1c. Therapeutic goals for HbA1c and preprandial glucose levels have been established based on the results of controlled clinical trials. Unfortunately, the majority of patients with diabetes fail to achieve their glycemic goals. Elevated postprandial glucose (PPG) concentrations may contribute to suboptimal glycemic control. Postprandial hyperglycemia is also one of the earliest abnormalities of glucose homeostasis associated with type 2 diabetes and is markedly exaggerated in diabetic patients with fasting hyperglycemia.
Several therapies targeted toward lowering PPG excursions are now available and have been shown to improve glycemic control as measured by HbA1c. However, many questions remain unanswered regarding the definition of PPG and, perhaps most importantly, whether postprandial hyperglycemia has a unique role in the pathogenesis of diabetic complications and should be a specific target of therapy. To address these issues and to provide guidance to health care providers, the American Diabetes Association (ADA) convened a consensus development conference on 24–26 January 2001 in Atlanta, Georgia.
A seven-member panel of experts in diabetes, endocrinology, and metabolism heard selected abstracts and presentations from invited speakers. The panel was then asked to develop a consensus position on the following questions:
1.
How is PPG defined?
2.
What is the relationship among PPG, FPG, and HbA1c?
3.
What is the contribution of PPG to the long-term complications of diabetes?
4.
Under what circumstances should people with diabetes be tested for PPG?
5.
What are the benefits and risks of specifically lowering PPG in an effort to achieve better glycemic control?
6.
What additional research needs to be performed to clarify the role of PPG in the medical management of diabetes?
Next Section
QUESTION 1: HOW IS PPG DEFINED?
The word postprandial means after a meal; therefore, PPG concentrations refer to plasma glucose concentrations after eating. Many factors determine the PPG profile. In nondiabetic individuals, fasting plasma glucose concentrations (i.e., following an overnight 8- to 10-h fast) generally range from 70 to 110 mg/dl. Glucose concentrations begin to rise ?10 min after the start of a meal as a result of the absorption of dietary carbohydrates. The PPG profile is determined by carbohydrate absorption, insulin and glucagon secretion, and their coordinated effects on glucose metabolism in the liver and peripheral tissues.
The magnitude and time of the peak plasma glucose concentration depend on a variety of factors, including the timing, quantity, and composition of the meal. In nondiabetic individuals, plasma glucose concentrations peak ?60 min after the start of a meal, rarely exceed 140 mg/dl, and return to preprandial levels within 2–3 h. Even though glucose concentrations have returned to preprandial levels by 3 h, absorption of the ingested carbohydrate continues for at least 5–6 h after a meal.
Since people with type 1 diabetes have no endogenous insulin secretion, the time and height of peak insulin concentrations, and resultant glucose levels, are dependent on the amount, type, and route of insulin administration. In type 2 diabetic patients, peak insulin levels are delayed and are insufficient to control PPG excursions adequately. In type 1 and type 2 diabetic individuals, abnormalities in insulin and glucagon secretion, hepatic glucose uptake, suppression of hepatic glucose production, and peripheral glucose uptake contribute to higher and more prolonged PPG excursions than in nondiabetic individuals.
Because the absorption of food persists for 5–6 h after a meal in both diabetic and nondiabetic individuals, the optimal time to measure postprandial glucose concentration must be determined. Practical considerations limit the number of blood samples that can be obtained. In general, a measurement of plasma glucose 2 h after the start of a meal is practical, generally approximates the peak value in patients with diabetes, and provides a reasonable assessment of postprandial hyperglycemia. Specific clinical conditions, such as gestational diabetes or pregnancy complicated by diabetes, may benefit from testing at 1 h after the meal.
http://care.diabetesjourn...rg/content/24/4/775.full
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But how long after a meal should you test? And do you start counting from when you start eating or when you finish?
A lot of people with diabetes are confused about this. But it is for questions like these that the American Diabetes Association and other organizations have developed guidelines, position papers, and consensus statements.
The American Diabetes Association's Consensus Statement on Postprandial Blood Glucose concludes that generally we should test two hours after the start of a meal (and women with gestational diabetes or pregnancy complicated by diabetes could benefit from testing after one hour). Testing two hours "after the start of a meal is practical, generally approximates the peak value in patients with diabetes, and provides a reasonable assessment of postprandial hyperglycemia."
Because of this, we should shoot for a target level of under 140 two hours after eating, says the American College of Endocrinology Consensus Development Conference on Guidelines for Glycemic Control. This panel says that people who don't have diabetes generally peak about an hour after the start of a meal and rarely exceed 140 mg/dl.
While some people still prefer to test one hour after starting a meal, most prefer to follow the guidelines. The best thinking in my view came from Helen, who wrote on a diabetes mailing list, "If I aim for pre-meal levels to occur an hour after eating, I chance going low two hours postprandial and for sure three hours postprandial. My blood glucose level tends to decline from hour two to hour three. Therefore I do not test one hour postprandial—there is nothing I would do with that information other than aggravate myself."
Guidelines for Testing and Everything
