METABOLIC
DISTURBANCES AND COMPLICATIONS OF THE DIABETIC STATE
There are only two major
sources of blood glucose: ex-ogenous, or
the ingestion of dietary carbohydrate, and
endogenous, which is contributed by hepatic and renal gluconeogenesis and hepatic glycogenolysis. Diabetes mellitus is a
metabolic disorder in which carbohydrate metabolism is reduced while that of
proteins and lipids is increased. In diabetics, exogenous and endogenous
glu-cose is not used effectively, and it accumulates in the blood (hyperglycemia). As blood glucose levels
in-crease, the amount of glucose filtered by the glomeruli eventually exceeds
the reabsorption capacity (Tm, trans-port maximum) of the proximal
tubule cells, and glu-cose appears in the urine (glucosuria). Protein catabo-lism and the rate of nitrogen excretion
are increased when blood insulin falls to low levels; stimulation of he-patic
gluconeogenesis converts amino acids to glucose. The catabolism of lipids and
fatty acids is also acceler-ated in the absence of insulin, leading to the
formation of ketone bodies, such as
acetoacetic acid, -hydroxybu-tyric acid, and acetone. Renal losses of glucose,
nitroge-nous substances, and ketone bodies promote osmotic diuresis that can
result in dehydration, electrolyte ab-normalities, and acid–base disturbances. Diabetic ke-toacidosis is the end result
of insulin deficiency in un-controlled type I diabetes.
Type II diabetics are less
prone to develop ketone bodies or diabetic ketoacidosis but may develop hyper-osmolar coma, a condition
characterized by severe hy-perglycemia and dehydration. Both diabetic
ketoacido-sis and hyperosmolar coma are medical emergencies that require prompt
insulin administration and intra-venous fluids.
Diabetes mellitus is
associated with many complica-tions that are increased in the setting of poor
glycemic control. Diabetes mellitus can cause microvascular complications
(e.g., retinopathy, nephropathy, and neu-ropathy) and macrovascular
complications (e.g., athero-sclerotic cardiovascular disease), associated with
dia-betic dyslipidemia (usually elevated triglycerides and low-density
lipoprotein cholesterol). Recent clinical tri-als have demonstrated that the
risk of developing chronic complications of diabetes is reduced by achiev-ing good
glycemic control. This can be accomplished by a combination of diet, exercise,
and rational pharmaco-logical therapy directly targeted to optimize diabetes
management.
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.