Chemistry: analytical and immunological testing – Tracers or tags
Reexamination Certificate
2002-08-27
2003-07-29
Wallenhorst, Maureen M. (Department: 1743)
Chemistry: analytical and immunological testing
Tracers or tags
C436S014000, C436S173000, C436S181000, C435S014000
Reexamination Certificate
active
06599750
ABSTRACT:
FIELD OF INVENTION
Use of
13
C glucose in an analytical assay to monitor glucose metabolism by measurement of labeled exhaled CO
2
is provided. A breath test and kit for performing the breath test are described for the diagnosis of diabetic indications and monitoring of glycemic control. The breath test utilizes the measurement of expired
13
C-labeled CO
2
following the ingestion of a
13
C-enriched glucose source.
REFERENCES
The following references are referred to by their numbers in parenthesis in this specification.
1. Martin B C, Warram J H, Krolewski A S, et al. Role of glucose and insulin resistance in development of type 2 diabetes mellitus: results of a 25-year follow-up study. Lancet 1992; 340: 925-9.
2. Lillioja S, Mott D M, Spraul M, et al. Insulin resistance and insulin secretory dysfunction as precursors of non-insulin-dependent diabetes mellitus; prospective studies of Pima Indians. N Engl J Med 1993; 329: 1988-92.
3. Beck Nielsen H, Groop L C. Metabolic and genetic characterization of pre-diabetic states. Sequence of events leading to non-insulin-dependent diabetes mellitus. J Clin Invest 1994; 94: 1714-21.
4. Matthaei S, Stumvoll M, Kellerer M, et al. Pathophysiology and pharmacological treatment of insulin resistance. Endocr Rev 2000; 21: 585-618.
5. The Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Report of the expert committee on the diagnosis and classification of diabetes mellitus. Diabetes Care 2001; 24(suppl 1).
6. Harris M I. Undiagnosed NIDDM: clinical and public health issues. Diabetes Care 1993, 16: 642-52.
7. World Health Organization. Prevention of diabetes mellitus; report of a WHO study group. Geneva: WHO, 1994; technical report series No. 844.
8. Meltzer S, Leiter L, Daneman D, et al. 1998 clinical practice guidelines for the management of diabetes in Canada. Can Med Assoc J 1998; 159 (suppl 8): S1-29.
9. Matthews D R, Hosker J P, Rudenski A S, et al. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia 1985; 28: 412-19.
10. Haffner S M, Gonzales C, Miettinene H, et al. A prospective analysis of the HOMA model: the Mexico City Diabetes Study. Diabetes Care 1996; 19: 1138-41.
11. Bonora E, Targher G, Alberiche M, et al. Homeostasis model assessment closely mirrors the glucose clamp technique in the assessment of insulin sensitivity. Diabetes Care 2000; 23: 57-63.
12. World Health Organization. Definition, diagnosis and classification of diabetes mellitus and its complications: Report of a WHO Consultation. Part 1. Diagnosis and classification of diabetes mellitus. Geneva: WHO, 1999.
13. Ganda O P, Day J L, Soeldner J S, et al. Reproducibility and comparative analysis of repeated intravenous and oral glucose tolerance tests. Diabetes 1978; 27:715-25.
14. Riccardi G, Vaccaro O, Rivellese A, et al. Reproducibility of the new diagnostic criteria for impaired glucose tolerance. Am J Epidemiol 1985; 121: 422-9.
15. Ko G T C, Chan J C N, Woo J, et al. Use of the 1997 American Diabetes Association Diagnostic criteria for diabetes in a Hong Kong Chinese population. Diabetes Care 1998; 21: 2094-7.
16. Ko G T C, Chan J C N, Woo J, et al. The reproducibility and usefulness of the oral glucose tolerance test in screening for diabetes and other cardiovascular risk factors. Ann Clin Biochem 1998; 35: 62-7.
17. Gabir M M, Hanson R L, Diabelea D, et al. The 1997 American Diabetes Association and 1999 World Health Organization criteria for hyperglycemia in the diagnosis and prediction of diabetes Diabetes Care 2000; 23: 1108-12.
18. Radziuk J. Insulin sensitivity and its measurement: structural commonalities among the methods. J Clin Endocrinol Metab 2000; 85: 4426-33.
19. CDC Diabetes Cost-Effectiveness Study Group. The cost-effectiveness of screening for type 2 diabetes. JAMA 1998; 280: 1757-63.
20. Hosker J P, Matthews D R, Rudneski A S, et al. Continuous infusion of glucose with model assessment: measurement of insulin resistance and &bgr;-cell function in man. Diabetologia 1985; 28: 401-11.
21. Emoto M, Kawagishi T, Nishizawa Y, et al. Homeostasis model assessment as a clinical index of insulin resistance in type 2 diabetic patients treated with sulfonylureas. Diabetes Care 1999; 22:818-22.
The entire disclosure of each of the above-referenced publications, patents and patent applications is incorporated herein in its entirety.
BACKGROUND OF THE INVENTION
Glucose tolerance is defined as the ability to properly utilize glucose. Diabetes is not a single disease, but an array of diseases that exhibit the common symptom of glucose intolerance, an impairment in glucose utilization.
The prevalence of diabetes in the general population is approximately 6-7%. Only about half of diabetics are actually diagnosed. Studies have shown that rates for persons with glucose intolerance are equal by sex and greater for blacks than for whites.
In general, the following types of diabetes have been recognized: type I diabetes mellitus, type II diabetes mellitus, secondary diabetes mellitus, impaired glucose tolerance and gestational diabetes mellitus. The general characteristics of the symptoms of diabetes include the following:
Polyuria (excretion of large quantities of urine)
Hyperglycemia (high blood glucose levels)
Glucosuria (abnormal presence of glucose in urine)
Polydipsia (excessive thirst)
Polyphagia (excessive hunger)
Sudden weight loss.
It has been observed that complications resulting from diabetes mellitus are the third leading cause of death in most developed countries. Diabetes is a risk factor for a variety of conditions including coronary heart disease, cerebrovascular stroke, neuropathy (nerve damage), nephropathy (kidney damage), retinopathy (eye damage), hyperlipidemia (excessive blood lipids), angiopathy (damage to blood vessels) and infection.
A number of different methods exist for determining a condition of intolerance for glucose. These include postprandial blood glucose, oral glucose tolerance test (OGTT), O'Sullivan glucose tolerance test (gestational test), hemoglobin Alc (Hb A
l
, Hb A
lc
), islet cell antibodies, glutamic acid decarboxylase (GAD) antibodies and insulin antibodies. Diabetes, however, is most readily detected when the carbohydrate metabolic capacity is tested. This is done by stressing the system with a defined glucose load as in the oral glucose tolerance test (OGTT).
The OGTT has been criticized, however, because many of the variables affecting test results are difficult to control. For instance: patients must be on a standardized carbohydrate diet at least three days before the test; the test requires an 8 to 16 hour fast; the test should only be performed on ambulatory patients; stress should be avoided; exercise should be avoided; various hormone imbalances can affect validity such as with: thyroxine, growth hormone, cortisol and catecholamines; various drugs and medications can affect validity such as: oral contraceptives, salicylates, nicotinic acid, diuretics and hypoglycemics; and evaluation should normally be corrected for age. The greatest disadvantage of the OGTT is that it is poorly reproducible and this limits its diagnostic usefulness.
Type 2 diabetes is a common condition, associated with significant morbidity and mortality. It is generally acknowledged that overt type 2 diabetes is preceded by a period of glucose intolerance which itself is preceded by a significant period of insulin resistance (1-5). It is now further recognized that typical diabetic complications can begin to develop during this “pre-diabetic” phase (3,6). The identification of persons at risk of developing overt type 2 diabetes has therefore taken on even greater importance. It has been suggested that if such persons could be easily identified, a lifestyle modification strategy could be implemented which might prevent their progression to type 2 diabetes with its attendant morbidities.
Because of the public health importance of type 2 diabetes, regular screening for this condition is now advocated (5,7,8). However,
Aspeslet Launa J.
Foster Robert T.
Lewanczuk Richard
Yatscoff Randall W.
Burns Doane , Swecker, Mathis LLP
Isotechnika Inc.
Wallenhorst Maureen M.
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