1-Birthweight and Type 2 diabetes
Recent observations suggest a relationship between low
birthweight and the development in middle age of insulin
resistance, Type 2 diabetes, and coronary artery disease. Those
who are smallest at birth and largest at one year of age are most
at risk.
2-Genetics of Type 2 diabetes
Type 2 diabetes has a strong genetic component, manifest in
the high concordance of diabetes in monozygotic twins,
familial clustering and differences in prevalence between
ethnic groups. An increasing number of specific genetic
defects are becoming recognised and some are described
below.
Recent observations suggest a relationship between low
birthweight and the development in middle age of insulin
resistance, Type 2 diabetes, and coronary artery disease. Those
who are smallest at birth and largest at one year of age are most
at risk.
2-Genetics of Type 2 diabetes
Type 2 diabetes has a strong genetic component, manifest in
the high concordance of diabetes in monozygotic twins,
familial clustering and differences in prevalence between
ethnic groups. An increasing number of specific genetic
defects are becoming recognised and some are described
below.
3-Type 2 diabetes in children and young people
Hitherto, childhood diabetes was witnessed in some ethnic
minorities and in those with the rare inherited MODY
syndromes described below.
Growing recognition now exists of
a substantial increase of this disease in the prosperous
industrialised nations. In the United States, between 8% and
45% of recently diagnosed cases of diabetes among children
and adolescents are Type 2, and the problem is increasing.
It is most likely to occur at 12 to 14 years of age, more
frequently in girls, and is strongly associated with obesity,
physical inactivity and a family history of Type 2 diabetes.
a substantial increase of this disease in the prosperous
industrialised nations. In the United States, between 8% and
45% of recently diagnosed cases of diabetes among children
and adolescents are Type 2, and the problem is increasing.
It is most likely to occur at 12 to 14 years of age, more
frequently in girls, and is strongly associated with obesity,
physical inactivity and a family history of Type 2 diabetes.
When young people of lean physique are discovered to have
Type 2 diabetes, it is important to attempt to identify whether
they may represent those with LADA and thus in need of
insulin. There is also evidence that in approximately
one-quarter of such patients diabetes is due to a
specific genetic defect including those of the MODY group
described below or other rare genetic syndromes.
4-Dominantly inherited Type 2 diabetes (MODY)
Seven genetic syndromes, three of which are shown in the
box at the top of page 2, cause MODY—defined as an early
onset of dominantly inherited Type 2 diabetes.
Type 2 diabetes, it is important to attempt to identify whether
they may represent those with LADA and thus in need of
insulin. There is also evidence that in approximately
one-quarter of such patients diabetes is due to a
specific genetic defect including those of the MODY group
described below or other rare genetic syndromes.
4-Dominantly inherited Type 2 diabetes (MODY)
Seven genetic syndromes, three of which are shown in the
box at the top of page 2, cause MODY—defined as an early
onset of dominantly inherited Type 2 diabetes.
Two (or at the very least one) members of such families should have been
diagnosed before 25 years of age, three generations (usually
first-degree) should have diabetes, and they should not
normally require insulin until they have had diabetes for more
than five years.
--Mitochondrial diabetes
Mitochondrial diabetes and deafness is a rare form of diabetes
maternally transmitted, and is related to the A3243G
mitochondrial DNA mutation.
diagnosed before 25 years of age, three generations (usually
first-degree) should have diabetes, and they should not
normally require insulin until they have had diabetes for more
than five years.
--Mitochondrial diabetes
Mitochondrial diabetes and deafness is a rare form of diabetes
maternally transmitted, and is related to the A3243G
mitochondrial DNA mutation.
Diabetes is diagnosed in the fourth to fifth decades, usually in thin patients with symptoms.
Patients respond better to sulphonylureas than to diet alone.
Diabetic microvascular complications do occur.
--Insulin resistant diabetesSome rare insulin resistant states exist in which hundreds or
even thousands of units of insulin may be ineffective. They are
often associated with lipodystrophy, hyperlipidaemia, and
acanthosis nigricans. Type A insulin resistance is due to genetic
defects in the insulin receptor or in the post-receptor pathway.
Patients respond better to sulphonylureas than to diet alone.
Diabetic microvascular complications do occur.
--Insulin resistant diabetesSome rare insulin resistant states exist in which hundreds or
even thousands of units of insulin may be ineffective. They are
often associated with lipodystrophy, hyperlipidaemia, and
acanthosis nigricans. Type A insulin resistance is due to genetic
defects in the insulin receptor or in the post-receptor pathway.
Type B insulin resistance occurs as a result of IgG
autoantibodies directed against the insulin receptor; it is
often associated with other autoimmune disorders such as
systemic lupus erythematosis, and it is much commoner in
women of African descent.
autoantibodies directed against the insulin receptor; it is
often associated with other autoimmune disorders such as
systemic lupus erythematosis, and it is much commoner in
women of African descent.
Management of these conditions
can be very difficult and specialist texts should be consulted
can be very difficult and specialist texts should be consulted
No comments:
Post a Comment