Consensus Guidelines for the Management of
Insulin-Dependent (Type 1) Diabetes — Chapter 3

3.0 TARGETS, INSULIN, HYPOGLYCAEMIA, DIET, and LIPIDS

3.1 Biomedical Targets for Diabetes Management
3.2 Insulin Therapy
3.3 Hypoglycaemia
3.4 Nutritional management
3.5 Lipids and ischaemic heart disease

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Targets

3.1 Biomedical Targets for Diabetes Management

• Type 1 diabetes must never be managed on the basis of symptoms alone.
• Two questions may be asked:
  1. Is it possible for each individual to approach each target more closely, without a counter-balancing deterioration in quality of life?
  2. For what percentage of patients is the service achieving these targets?
• The targets are based on evidence of what levels of abnormality constitute added health risk (for example of retinopathy through hyperglycaemia). Failure to attempt to approach the targets more closely, if this can be done without deterioration in quality of life (or acute risk), is inadequate care.
• It is however inappropriate to approach target levels too closely where this adversely affects the patient.

Table 3.1.1 Biomedical targets for diabetes control

                               Good     Borderline    Poor
—————————————————————————————————————————————————————————————
  Self-monitored blood glucose
       fasting/pre-prandial
            mg/dl              80-110    111-140      >140
            mmol/l            4.4-6.1    6.2-7.8      >7.8
       post-prandial
            mg/dl             100-145    146-180      >180
            mmol/l            5.5-8.0    8.1-10.0     >10.0
  Glycated Hb (%Hb)*          <+3SD      3SD-5SD      >5SD
       HbA1c (normal <6.1%)   <6.5       6.5-7.5      >7.5
       HbA1  (normal <7.5%)   <8.0       8.0-9.5      >9.5
  Total serum cholesterol
            mg/dl             <200       200-250      >250
            mmol/l            <5.2       5.2-6.5      >6.5
  Fasting serum triglycerides
            mg/dl             <150       150-200      >200   
            mmol/l            <1.7       1.7-2.2      >2.2   
  Body mass index  (kg/m/m)                                  
       male                   <25.0      25.0-27.0    >27.0  
       female                 <24.0      24.0-26.0    >26.0  
—————————————————————————————————————————————————————————————

3.1.1 Recommendations for metabolic targets (see Table 3.1.1)

• Glycated haemoglobin estimation should be measured regularly in every patient.
• Single (clinic) blood glucose estimations are not a reliable measure of blood glucose control due to high variance between days and between times of day.
• Normal glycated haemoglobin levels are often associated with unrecognized recurrent hypoglycaemia particularly during sleep. Such levels should prompt caution and investigation.
• Target bedtime glucose levels are generally 6.0-7.5 mmol/l (110-135 mg/dl) to reduce the risk of night-time hypoglycaemia ( hypoglycaemia ).
• Fructosamine is not an adequate substitute for glycated haemoglobin estimation, but fulfils some of the same functions.
• The blood pressure target is <=140/85 mmHg (1st/5th, lying, 5 min rest
• The need to attain these targets is increased by the finding of microalbuminuria, defined as >20 µg/min overnight or >30 mg/24-h) ( nephropathy ).
• Similarly the presence of other risk factors (such as adverse family history) will affect the power of failure to achieve targets in advocating more intensive interventions.
• Attainment of the non-metabolic target of "diabetes interfering little with the patient's general and social well-being" will help metabolic control.

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Targets

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Insulin

3.2 Insulin Therapy

• IDDM is a simple hormonal deficiency disease, and is therefore simply managed by insulin replacement therapy.
• Islet B-cells normally regulate insulin delivery on a minute to minute basis ¸ and as yet there is no technological means of replacing that function.
• Additionally subcutaneous absorption is slow, erratic, and subject to physiological and external factors.
• As a result insulin therapy has to be instituted individually and must be supported by patient education, regulation of dietary behaviour and physical exercise, and the use of self-monitoring.

The aims of insulin therapy are:

• To achieve optimum metabolic control by mimicking endogenous insulin secretion as closely as possible during normal daily life.
• To avoid the experience and risks of hypoglycaemia ( hypoglycaemia ).

3.2.2.1 General advice

• Insulin preparations of any species may be used; method of manufacture is not clinically relevant.
• Insulin preparations should be of adequate purity to avoid lipoatrophic injection site abnormalities, or other insulin-antibody induced problems.
• Insulin regimens should be composed of available preparations of short- and intermediate-acting formulations (Table 4). Long-acting formulations (24-h effect) are not generally available at present.
• U100 (100 U/ml) concentration insulin is increasingly used in Europe; further standardization is desirable, but U40 (40 U/ml) insulin is entirely satisfactory.
• For routine therapy insulin can only be given by the subcutaneous route; other routes are for special ( surgery , ketoacidosis, CAPD) or experimental (intraperitoneal, nasal) use only.

Table 3.2.1 Time-action characteristics of available insulin preparations

                                 Time (hours)
                           onset    maximum    extent
———————————————————————————————————————————————————————
Short-acting             0.25-1.0   1.5-4.0   5.0- 8.0
Intermediate-acting*     0.5 -2.0   3.0-6.0   8.0-14.0
———————————————————————————————————————————————————————

3.2.2.2 Insulin regimens

• Once daily injection regimens are rarely suitable for people with IDDM.
• At least two daily injections of a mixture of short- and intermediate-acting insulin formulations are needed to attempt to obtain optimal blood glucose control.
• Possible regimens are therefore:
  1. twice daily mixtures of short- and intermediate-acting insulin
  2. twice daily short- and intermediate-acting insulin, but with the evening intermediate-acting given at bedtime
  3. multiple pre-prandial injections of short-acting insulin, with an intermediate-acting insulin preparation given at bedtime.
  4. Unusual regimens may be justified in the presence of other illness, in patients with short life-expectancy, in the honeymoon period after diagnosis, and in the rare patients with psychological problems from injections.

3.2.2.3 Insulin dose

• Inadequate blood glucose control requires review of behavioural and dietary factors before insulin dose adjustment is considered.
• Insulin dose adjustments may be made by patients or professionals on the basis of self-monitored results validated by glycated haemoglobin estimation ( self-monitoring ) ( metabolic control ).
• Insulin dose adjustment must take account of the problems of hypoglycaemia when striving to achieve the metabolic targets.
• There are no rules of insulin dosage, but average requirements are often 0.5-1.0 U/kg/day; basal metabolic requirements are 40-60 % of the total.
• Dose changes, especially of intermediate-acting insulin, should be evaluated over a few days before further changes are made.

3.2.2.4 Insulin delivery devices

• Plastic fixed-needle syringes are preferable to glass syringes, and may be reused while the needle is sharp if precautions are taken to maintain hygiene.
• Insulin delivery devices, such as injection pens (including pre-filled syringes) are reliable, and enhance quality of life through flexible life-styles, and through management independence in the elderly.
• Gun and jet injectors are not recommended.
• Continuous subcutaneous insulin infusion (CSII) is suitable for selected patients in centres with special expertise.
• Implanted insulin pumps are in general a research tool only.
• Additional devices such as magnifiers, pre-set syringes, and syringe dose gauges for the visually impaired, or spacing devices for those with tremor or psychological problems, should be available to those with special needs.
• The provision of devices or arrangements for safe disposal of needles is desirable.

3.2.2.5 Injection sites

• The abdominal wall is preferable for its faster absorption of short-acting insulin.
• The thigh is preferable for its slower absorption of intermediate-acting insulin formulations. The upper lateral gluteal region is an alternative.
• Rotation of injection sites should be encouraged within these areas to reduce the chance of scarring and lipohypertrophy which can interfere with absorption.
• Patients should be educated as to the factors influencing insulin absorption rate, such as physical activity, ambient temperature, and lipohypertrophy.

3.2.2.6 Injection technique

• Assessment of patient attitude, vision and dexterity can avoid later problems.
• Cleaning of injection sites is not generally necessary.
• Injections should be given into the deep subcutaneous tissue into a broad pinch of skin at a 45° angle, or at a 90° angle where the subcutaneous layer is greater than needle length.
• Injection sites and skills should be checked yearly, or more often where blood glucose control is sub-optimal.

3.2.2.7 Special circumstances

• Insulin should never be omitted during intercurrent illness; extra insulin is often required, self-monitoring should be intensified, substitute carbohydrate taken if food is not tolerated, and urine tested for ketones.
• Less insulin may be taken before predicted exercise.
• Appropriate adjustments (including changes to cope with time zones) may be necessary when travelling.

3.2.3 Education for insulin therapy

• knowledge of insulin types and names
• knowledge of safe storage conditions
• ability administer correct insulin doses
• understanding of the variation in absorption of insulin and influence of injection site rotation and exercise
• ability to prevent, recognize, and treat hypoglycaemia
• ability interpret and use self-monitored test results
• knowledge of emergency contact routes and methods
• sick day management
• travel advice
• responsibility for safe disposal of syringes/needles
• wearing of personal identification in regard of insulin therapy.

3.2.4 Failure of insulin therapy

• undetected psychosocial problems
• intercurrent illness (chronic infection, endocrine disease)
• poor injection technique or injection sites
• changed eating habits ( diet ).

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Insulin

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Hypoglycaemia

3.3 Hypoglycaemia

• Hypoglycaemia on insulin therapy is feared, inconvenient, and often unpleasant
• Events requiring assistance affect 20 % of patients per year; some form of reaction affects 95 % of patients per year
• Cognitive dysfunction may be detected when blood glucose concentrations fall below 3.5 mmol/l (65 mg/dl), and overt neuroglycopenic signs and symptoms below 2.5 mmol/l (45 mg/dl)
• Autonomic activation occurs at around the same level, with classical signs and symptoms, and resulting in glucose counter-regulation
• Where autonomic symptoms are at a lower threshold or absent (hypoglycaemia unawareness), or ignored, severe cognitive disturbance and decreased conscious level may occur
• Prolonged profound hypoglycaemia can result in patient death, although this is rare
• Recurrent severe hypoglycaemia may result in neurological damage
• There is a possibility that recurrent undetected hypoglycaemia may cause a gradual loss of intellectual ability
• Recurrent attacks can have detrimental effects on a patient's work and private life.

     missing meals                   errors in insulin dosage
     smaller meals than usual        inappropriate regimens
     increased physical activity     hypoglycaemia unawareness
     alcohol                         errors in administration
     renal insufficiency             change in injection site
     ß-adrenergic blocker therapy    inappropriate doses
     previous hypoglycaemic events

Taken together, the evidence does not support the hypothesis that the species of insulin is associated with any change in hypoglycaemia unawareness or severe hypoglycaemia in some patients

3.3.1 Recommendations for the management of hypoglycaemia

Prevention of hypoglycaemia requires:

• adequate education of patients as part of a structured programme
• intermittent review of understanding of hypoglycaemia
• regular review of blood glucose profiles, insulin dose distribution, and experience of hypoglycaemia
• high professional awareness of the problem of nocturnal hypoglycaemia
• reporting of unrecognized/not-remembered events by family/friends
• professional alertness to changes in renal or endocrine function, or the effects of autonomic neuropathy particularly through gastroparesis.

Diagnosis can be by:

• self-monitoring for self- or family-treated events (measurement is desirable on all occasions)
• laboratory confirmation of the results of rapid methods for patients with decreased conscious level (but treating before result available)
• clinical acumen if blood tests are difficult or appear unreliable.

Management involves:

• Giving the conscious patient 10-20 g of glucose (or equivalent) and repeat this in 20 min if necessary; follow with long-acting carbohydrate
• Treating the unconscious patient with 1 mg glucagon IM or 20-30 ml 30-50 % glucose IV; do not use glucagon after significant alcohol consumption; on recovery oral carbohydrate or a light meal should be taken to prevent relapse
• Glucagon by injection is only useful if companions are instructed in its use; review is required to ensure supplies do not exceed expiry dates.
• Reviewing the cause of the event

3.3.2 Special problems in the management of hypoglycaemia

3.3.2.1 Hypoglycaemia unawareness

This can be a major source of psychological, social, and work-related problems. It occurs with increasing duration of diabetes and is then common, in particular in those patients with good blood glucose control. Hypoglycaemia unawareness may increase after an episode of hypoglycaemia, and during sleep or with lowered body temperature.

It is managed by:

• counselling on the mechanisms involved
• training in the recognition of neuroglycopenic symptoms
• review of other aspects of management
• review of the appropriateness of management goals (less tight control)
• counselling on resulting life-style problems.

3.3.2.2 Nocturnal hypoglycaemia

This often goes undetected by patients and professionals, but less often by companions. It may present as a severe night-time reaction. Detection is by morning symptoms, measurement of 0300 h blood glucose levels, and questioning of companions. Normal glycated haemoglobin levels should be treated as suspicious. It is not a significant cause of pre-breakfast hyperglycaemia.

Its occurrence may be affected by the dose of intermediate-acting insulin preparations given in the evening, but also from larger doses of evening short-acting insulin, and even morning intermediate-acting insulin preparations. Pre-bed snacks should be of longer-acting carbohydrate.

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Hypoglycaemia

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Nutrition

3.4 Nutritional Management

The objectives of nutritional management are:

• to avoid excessive swings in blood glucose concentration despite the non-physiological profiles of insulin delivery ( insulin )
• to avoid hypoglycaemia ( hypoglycaemia )
• to achieve optimal blood lipid status ( lipids )
• to achieve general nutritional requirements
• to maintain optimal body weight.

3.4.1 Recommendations on Dietary Management

• Calorie intake should be appropriate to desirable body weight.
• Calorie distribution should reflect the patient's life-style and desires, as well as insulin regimen and local circumstances.
• Healthy eating should be encouraged.
• Regular meals and snacks, where appropriate, are recommended.
• In general carbohydrate intake should be higher, and fat intake lower than that of most Europeans, but not different from recommendations for the population in general. The proposed contribution to energy intake should be:
  • Fat - saturated fat <10 %. Excess saturated fat may be replaced with monounsaturates, or polyunsaturates (up to 10 %), or by carbohydrate
  • Carbohydrate - around 50-55 %. The use of foods containing soluble fibre is recommended in a carbohydrate rich diet. Simple sugars need not be rigorously excluded from the diet but often need to be limited
  • Protein - around 15 % or less
• Special circumstances may dictate variation to these recommendations. Where nephropathy is developing protein intake should be <1.0 g/kg.
• Excessive salt intake (>7 g/day) should be discouraged.
• Special 'diabetes' food products are unnecessary (and are expensive and fattening). Non-calorific sweeteners may be useful.
• Alcohol intake should follow healthy guidelines, but moderation is important in the obese or those with hypertension or hypertriglyceridaemia. It should accompany carbohydrates to reduce the risk of serious hypoglycaemia, and the late hypoglycaemic effect discussed with the patient.

3.4.2 Meal patterns

3.4.2.1 Twice daily insulin regimens ( insulin )

Start with three meals and three snacks, but modify these according to self-monitored blood glucose levels. Thus a small breakfast is often all that is needed, and is often preferred by patients. The afternoon snack only exacerbates hyperglycaemia in some patients. The evening snack may be better taken at bedtime, or split into two.

3.4.2.2 Multiple injection regimens ( insulin )

Snacks can still help attain better blood glucose control, but again self-monitoring should be used to learn what is necessary and desirable.

On multiple injection regimens it is generally easier to adjust meal timing and content (together with insulin doses) without affecting blood glucose control. Care must be taken to avoid extra total calories however, or weight gain will result

3.4.3 Physical exercise

Physical exercise can benefit insulin sensitivity, hypertension, and blood lipid control and should be taken regularly for optimum effect; however it does increase the risk of acute and delayed hypoglycaemia ( hypoglycaemia ).

• For regular exercise a prospective reduction in insulin dose may be advised; self-monitoring can be used to optimize this. Additional carbohydrate will otherwise be necessary; foods containing simple sugars may be useful in prolonged exercise.
• Warnings must be given about delayed hypoglycaemia especially with more prolonged, severe, or unusual exercise.
• Self-monitoring assists in learning the individual's exercise response.
• Exercise during insulin deficiency will raise glucose and ketone levels.

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Nutrition

IDDM CONSENSUS GUIDELINES Chapter 3 MANAGEMENT: Lipids/Heart

3.5 Lipids and Ischaemic Heart Disease

• IDDM when moderately controlled is not as such associated with a dyslipidaemia.
• However, large vessel disease is common after many years, especially if diabetic renal disease occurs. It is the major cause of mortality.
• Dyslipidaemia is often found in patients with microalbuminuria/nephropathy ( nephropathy )
• Other risk factors are as for the non-diabetic population, but should be managed more aggressively

3.5.1 A strategy for the management of arterial risk in people with IDDM:

• Educate people about the risks from the time of diagnosis
• Stop smoking
• Encourage healthy eating (especially reduction in saturated fat intake) ( nutrition )
• Prescribe a programme of regular physical exercise ( exercise )
• Screen for lipid disorders at least annually treat aggressively ( metabolic targets )
• Screen for diabetes risk factors (microalbuminuria, hypertension) similarly ( nephropathy )
• Treat lipid abnormalities more aggressively than for the general population with the same risk factor profile, particularly if microalbuminuria detected
• Prescribe low-dose aspirin for those with known macroangiopathic lesions
• In adults enquire after angina annually, and treat accordingly avoid non-selective ß-adrenergic blockers
• Identify silent myocardial ischaemia in higher risk patients. Consider angioplasty and bypass grafting as for non-diabetic patients

IDDM CONSENSUS GUIDELINES Chapter 3.5 MANAGEMENT: Lipids/Heart