1. Dept of Diabetes and Endocrinology, Connolly Hospital, Blanchardstown
Diabetes Mellitus
Prof Seamus Sreenan
Dept of Diabetes and Endocrinology, Connolly Hospital, Blanchardstown
Mini Med School
November 30th, 2011

2. Learning Objectives At the end of this talk you should understand:
What diabetes mellitus means
The difference between types-1 and -2 diabetes
How the different types are treated
The reasons for the current epidemic of diabetes and how it can be prevented
What the complications of diabetes are and how they can be prevented

3. What is Diabetes?
Diabetes Mellitus (sugar diabetes) is a disease characterized by high levels of sugar (glucose) in the blood
Fasting glucose ≥ 7.0 (mmol/L)

4. Blood sugar and health Sugar (glucose) is an important source
of energy
Insulin is produced
by the pancreas when
blood sugar is high
What is eaten is
absorbed into
the blood
Insulin keeps blood
sugar level within
the normal range
for health

5. Islet of Langerhans:
Pancreas contains insulin-making cells in “islets”
Insulin b-cells

6. Diabetes in a ‘nutshell’
Insufficient insulin to meet the body’s needs
Either a complete lack (type 1) or relative lack (type 2)
Results in raised blood glucose levels
Untreated diabetes results in short-term symptoms and serious long-term complications
Treatment aims to keep blood glucose levels as close to the normal range as safely possible
Aim: Very basic introduction to diabetes for an audience that may not know a great deal about the disease area. NB can refer them back to their press packs which have detailed background information on diabetes and complications

7. Complications of Diabetes
Short term:
Symptoms of diabetes
Dehydration
Diabetic Coma
Infections
Long term:
Kidney
Eye
Heart
Circulation
Amputation

8. Symptoms of Diabetes
People with diabetes often have typical complaints (symptoms):
Thirst and frequent drinking
More frequent urination, particularly at night
Unexplained weight loss
Fatigue
Blurred vision
Frequent infections : skin, genital

9. Case 1 JN 32 year old male Referred to Emergency Dept by GP
Complaining of thirst, excessive urination, half stone weight loss in the last 6 weeks
No relevant past history
First cousin has diabetes on insulin
On no regular medications
Thin man
Blood sugar level = 24.7 mmol/L

10. What type of diabetes does JN have?
There are 2 main types of diabetes:
Type 1 (15%): Due to total lack of insulin – insulin treatment is required for life
Type 2 (85%): Plenty of insulin which does not work very well in the body. Insulin treatment may be required at some stage but is not required in all patients

11. Differences between type-1 and type-2 Diabetes Mellitus
Young age
Normal BMI, not obese
No immediate family history
Short duration of symptoms (weeks)
Can present with diabetic coma (diabetic ketoacidosis)
Insulin required
Type 2
Middle aged, elderly
Usually overweight/obese
Family history usual
Symptoms may be present for months/years
Do not present with diabetic coma
Insulin not necessarily required
Previous diabetes in pregnancy
These differences are not absolute

12. JN Young age Thin No immediate family history
Short duration of symptoms
Insulin treatment required
All point to probable type-1 diabetes

13. The Miracle of Insulin Patient J.L., December 15, 1922
February 15, 1923

14. Treatment of Type-1 Diabetes Mellitus:
Insulin must be administered into the subcutaneous pocket between fat & muscle & avoid injection into fat or muscle.
Can be administered by needle and syringe or by pen device

15. Alternative way to deliver insulin treatment:
Continuous insulin infusion (insulin pump)

16. Islet replacement treatment
Aim to replace the need for insulin treatment
(Kidney) Pancreas transplantation
Islet transplantation – not available in Ireland
Anti-rejection drugs required
Stem cell transplantation - experimental

17. Case 2 Ms AJ, a 45 year old woman is concerned she may have diabetes
She had diabetes during her last pregnancy managed with diet
Lately she has been feeling tired but otherwise has no complaints
Her mother and one of her two sisters already have diabetes treated with tablets
She has been overweight since her last pregnancy and has taken a tablet for blood pressure for the last 2 years
She is obese, body mass index 34.5
Blood pressure is 140/90 but otherwise her examination is normal
She undergoes a testing and her fasting glucose is 9.4 mmol/L
Obese, strong family history, aged in 40s, previous history of diabetes in pregnancy all point to type-2 diabetes

18. Natural History of Type 2 Diabetes
Normal Prediabetes Type 2 diabetes
Insulin resistance
Increasing insulin resistance
Insulin
secretion
Hyperinsulinemia,
then islet cell failure
There is a temporal relationship between insulin resistance, insulin secretion and the development of diabetes.
In the early stages, as insulin resistance rises, there is a compensatory increase in insulin secretion and the individual remains normoglycemic.
In the long term, as the b-cells begin to fail, insulin secretion falls, abnormal glucose tolerance and hyperglycemia become apparent and frank type 2 diabetes develops.
International Diabetes Center (IDC), Minneapolis, Minnesota.
After meal glucose
Abnormal
glucose tolerance
Fasting glucose
High sugar levels
Adapted from International Diabetes Center (IDC), Minneapolis, Minnesota.

19. Treatment of Type-2 Diabetes
Diet/ exercise
Oral monotherapy
Oral combination
Oral +/- insulin
Insulin
Diet and exercise my control condition for some time
Variety of tablets available when diet exercise no longer work
Tablets can be used in combination with each other or with insulin
Insulin can also be used alone
Stepwise approach
The traditional stepwise approach aims primarily to control acute symptoms.
Dietary measures and exercise are not usually sufficient to control glycemia beyond the first year of therapy.
If oral monotherapy proves inadequate, combination therapy is usually started. If this also proves unsuccessful, conversion to insulin is the next step, either alone or in combination with an oral agent.
In the majority of cases, the stepwise approach does not lead to sustained control.
Many physicians intensify treatment only when symptoms of poor glycemic control become apparent, rather than when glycemic targets are not reached.
Early, aggressive approach
This approach to type 2 diabetes management avoids the risk of early treatment failure by adopting an intensive therapeutic strategy immediately upon diagnosis.
Combinations of agents with complementary modes of action targeting the dual defects underlying type 2 diabetes (insulin resistance and b-cell dysfunction) are most likely to support tight, long-term glycemic control.
Furthermore, combination therapy should be considered earlier in the regimen to provide additional glycemic control.
Campbell IW. Br J Cardiol 2000; 7:625–631.

20. Prevalence of Diabetes
Diabetes is very common
It is becoming more common (particularly type-2)
It affects about 200,000 Irish people
10% of the health budget spent on diabetes

21. Reason for increasing prevalence of type-2 diabetes
The disease is reaching epidemic proportions because:
Rates of overweight/obesity have increased
We have become a physically inactive species
Our diets are increasingly unhealthy

22. Everyone should know their BMI!
Overweight and obesity are diagnosed by measuring weight and height (Body Mass Index (BMI)):
Weight in Kg
Height in metres2
Normal = 20-25
Overweight = 25-30
Obese = more than 30
Everyone should know their BMI!
BMI =

25. Can Diabetes be Prevented?
To be able to prevent a disease we need to be able to indentify people at particular risk of developing it

26. Risk factors for type 2 diabetes
Certain people are more at risk of diabetes:
Those who are overweight/obese
People with a family history of diabetes
Women who had diabetes during pregnancy or have had a baby weighing more than 9lbs
Physically inactive people
Certain ethnic groups (african, american indian, asian)
People who have high blood pressure or high cholesterol
Age more than 45 years

27. Can Diabetes be Prevented?
Risk of Type 2 Diabetes can be reduced:
Losing weight
Taking regular exercise : walking for 30 mins per day
Eating healthier food:
 Less fat (burgers, fries, crisps, sweet foods)
 More fibre (fruit and vegetables, wholegrain alternatives for rice, bread)
Cutting down on alcohol consumption
Ultimate aim is to reduce the longterm complications

28. Can the longterm complications be prevented?
Type-1
1993: Study showed for the first time that good sugar control can prevent long term complications affecting eyes/kidneys/nerves
Type-2
1998: Similar study showed same conclusion for type-2
Important therefore to know that sugar control is good and monitor frequently

29. Diabetes Mellitus: Self Monitoring SMBG
Patients can draw blood frequently to monitor their glucose levels.
A glucose monitor is used to check the sugar as required

30. Glycosylated Hemoglobin: HbAlc
Blood test that measures the amount of glucose that has been incorporated into the hemoglobin protein of the red blood cell (RBC).
Reflects the lifespan of a RBC, so test will reveal the effectiveness of diabetes therapy for the preceding 8-12 weeks.
HbA1c levels remain more stable than sugar levels.
Not affected by short-term fluctuations in sugar
Normal is 4-6%
Evaluated periodically (1-2 per year if well controlled, more frequently if not)

31. A1c and relative risk of complications (type 1 diabetes) :20
Retinopathy
Nephropathy
Neuropathy
Microalbuminuria 15 13
Aim for AIc of < 7% 11 9
Relative Risk (%) 7 5 3
Aim: To show why A1c control is important relating level to complications:
Good glycaemic control is essential to reduce the risk of diabetic complications
Based on the Diabetes Control and Complications Trial data that compared conventional with intensive regimens, the relative risk for microvascular complications such as diabetic retinopathy, nephropathy, neuropathy, and microalbuminuria increases with increasing levels of A1C1-3
The relative risk of complications is set to “1” for an A1C of 6%1
It is important to note that the risk gradient is continuous with no glycaemic threshold for developing complications1 1 6 7 8 9 10 11 12
A1c (%)
DCCT, Diabetes Control and Complications Trial.
1. Adapted from Skyler JS. Endocrinol Metab Clin North Am. 1996;25:
2. DCCT. N Eng J Med. 1993;329:
3. DCCT. Diabetes. 1995;44:
1. Skyler JS. Diabetic complications: the importance of glucose control. Endocrinol Metab Clin North Am. 1996;25:
2. The Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitis. N Engl J Med. 1993;329:
3. Diabetes Control and Complications Trial Research Group. The relationship of glycemic exposure (HbA1C) to the risk of development and progression of retinopathy in the Diabetes Control and Complications Trial. Diabetes. 1995;44:

32. How to prevent the complications
Factors other than blood sugar increase likelihood of complications and should be managed
Complications can be delayed/prevented by:
Controlling blood sugars: sticking to diet/exercise programme, taking medication as prescribed
Controlling blood pressure: diet, salt restriction, medication
Controlling cholesterol levels: diet, statin tablets
Stopping smoking
Taking aspirin?

33. Useful websites Diabetes Federation of Ireland:
American Diabetes Association
Irish Nutrition and Dietetic Institute
Juvenile Diabetes Research Foundation