2: Initial management and education

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Section 2 Initial management and education

Clinical presentation of diabetes

The clinical presentation of diabetes is heterogeneous, ranging from asymptomatic type 2 diabetes to the dramatic life-threatening conditions of diabetic ketoacidosis (DKA) and hyperosmolar non-ketotic coma (HONK). Patients with type 2 diabetes are often detected by opportunistic screening such as urinalysis or routine blood glucose tests in general practice, at health insurance checks or during attendance at hospital for an unrelated problem. This heterogeneity in presentation reflects not only the relevant diagnostic category into which the patient falls (type 1 or type 2), but also the point in the natural history of the disorder at which the diagnosis is made. Patients may present with macrovascular complications or the specific microvascular complications of diabetes.

Type 1 diabetes

The clinical presentation of type 1 diabetes in younger patients is usually acute with classical osmotic symptoms (Table 2.1).

Table 2.1 Presenting features of type 1 diabetes

Osmotic symptoms Associated symptoms
Thirst Muscular cramps
Polyuria Blurred vision
Nocturia
Weight loss
Fatigue and lassitude
Fungal or bacterial infection, usually orogenital and cutaneous, respectively

Symptoms will usually have been present for only a few weeks; weight loss may predominate. In these circumstances, weight loss reflects catabolism of protein and fat resulting from profound insulin deficiency. If the hyperglycaemia is marked, the patient may become severely dehydrated.

Associated symptoms, particularly blurred vision may occur, although these are generally less prominent. Although the islet β-cell destruction of type 1 diabetes is a process that occurs gradually. It is very uncommon to detect type 1 diabetes during the early asymptomatic stages of the condition. Once symptoms appear, diagnosis may sometimes be expedited by awareness of symptoms in other family members with diabetes. Despite the presence of significant osmotic symptoms, patients sometimes do not seek medical advice and may present in DKA (see Table 1.4).

DKA is a life-threatening medical emergency requiring hospitalization. The diagnosis and management of DKA is considered in more detail in Section 4.

Type 2 diabetes

The majority of patients with type 2 diabetes are diagnosed at a relatively late stage of a long pathological process that develops and progresses over many years.

The presenting clinical features of type 2 diabetes (Table 2.2) range from none at all to those associated with the dramatic and life-threatening hyperglycaemic emergency of the hyperosmolar non-ketotic syndrome. In many patients with lesser degrees of hyperglycaemia, symptoms may go unnoticed or unrecognized for many years; such undiagnosed diabetes carries the risk of insidious tissue damage.

Table 2.2 Presenting features of type 2 diabetes

None – asymptomatic patients identified by screening
Osmotic symptoms

Infection

Macrovascular complications

Microvascular complications

Associated conditions

Classical osmotic symptoms are may be present in type 2 diabetes – with the notable exception of significant weight loss, which is less common. However, a high index of clinical suspicion must be maintained so that asymptomatic cases are not missed. The absence of weight loss reflects the presence of sufficient secretion of endogenous insulin to prevent catabolism of protein and fat. Most patients with type 2 diabetes are overweight or obese, adding to their insulin resistance and hyperinsulinaemia. However lean type 2 diabetes is a definite entity particularly in developing countries.

Patients with diabetes tend to present in four main ways:

History and initial physical examination

Having obtained a detailed history, a physical examination should be undertaken (Table 2.3). The consultation should take place in appropriate and comfortable circumstances.

The mode of diagnosis and presence of symptoms should be recorded.

Family history of diabetes should be reviewed.

For women, enquiry into obstetric (stillbirths, large babies, gestational diabetes) and menstrual history (oligomenorrhoea, especially with features of hyperandrogenism) may be relevant.

Associated conditions (see Section 1), predisposing and aggravating factors should be identified.

A detailed history of drug use, smoking habits and alcohol consumption is required along with an enquiry into habitual physical activity and sporting interests.

Height and weight (plus waist circumference) need to be recorded and body mass index calculated.

Blood pressure should be measured carefully; lying and standing pressures should be recorded if there is any suggestion of postural hypotension arising from autonomic neuropathy. In diabetes there may be a postural drop with few or no symptoms.

Evidence of established diabetic complications including neuropathy (including autonomic dysfunction where appropriate) should be sought diligently at diagnosis in patients with type 2 diabetes (see Section 5).

Unless contraindications exist, notably angle-closure glaucoma, the fundi should be examined through pharmacologically dilated pupils in all patients with type 2 diabetes, as well as in patients with features that are not classical of autoimmune type 1 diabetes.

Features of other endocrinopathies, signs of marked insulin resistance and specific syndromes of diabetes such as the lipodystrophies are rare.

Table 2.3 Components of the comprehensive diabetes evaluation

Medical history

Physical examination Laboratory evaluation Referrals

BMI, body mass index; CHD, coronary heart disease; DKA, diabetic ketoacidosis; DSME, diabetes self-management education; GFR, glomerular filtration rate; HDL, high density lipoprotein; LDL, low density lipoprotein; MNT, medical nutrition therapy; PAD, peripheral arterial disease.

Source: American Diabetes Association (2011). Reproduced with permission.

Physical examination of the patient with newly presenting type 1 diabetes is usually unremarkable, although there may be evidence of recent weight loss and occasionally signs compatible with dehydration. Features of orogenital candidiasis or cutaneous sepsis are not uncommon, but are non-specific. The presence of vitiligo is consistent with the presence of autoimmune disease.

Nephropathy

Proteinuria is the hallmark of diabetic nephropathy. As with the other microvascular complications of diabetes, the development of nephropathy is closely related to the duration of diabetes.

Type 2 diabetes

In addition to early nephropathy, the presence of microalbuminuria may reflect a further increase in risk of macrovascular disease (see p. 199). However, because nephropathy can develop during the asymptomatic phase preceding diagnosis, plasma creatinine should be checked, especially if Albustix-positive (indicative of urinary protein losses of 500 mg/day or more; see p. 200).

Initial management

Having confirmed the diagnosis of diabetes, the crucial clinical question is whether insulin treatment is required. In the young patient with acute osmotic symptoms, weight loss and ketonuria, the decision to start insulin is straightforward. Similarly, the overweight or obese middle-aged or elderly patient with minor symptoms will usually be a candidate for a trial of dietary manipulation followed by metformin. In reality very few patients (< 20%) manage with diet alone for the usually advised period of 3 months.

Other oral agents including sulphonylureas, pioglitazone, gliptins etc. can be used from diagnosis, in addition to appropriate dietary measures.

Most importantly, the patient should be treated according to clinical need. However, an attempt should be made to place the patient with diabetes within the classification system. Often this assignment to a particular category is not possible with certainty and becomes clear only later. Initial therapy, therefore, does not necessarily confirm the aetiology. The difficulty at diagnosis centres on the degree of endogenous insulin deficiency, the rate of β-cell deterioration, the degree of insulin resistance and the presence of any intercurrent illness. Thus, patients with what proves ultimately to be type 1 diabetes will sometimes be treated with a trial of oral antidiabetic drugs, usually because the clinical and biochemical features were not classical; conversely, patients with type 2 diabetes may need insulin temporarily at diagnosis, especially if there is significant intercurrent illness.

It can sometimes be difficult to decide whether a newly presenting, middle-aged, non-obese patient with moderately severe hyperglycaemia has type 2 diabetes that will respond adequately to oral antidiabetic agents or whether the patient would be better treated with insulin from the outset. In this context, it should be remembered that, although relatively uncommon in the elderly, type 1 diabetes might present at any age.

The situation is complicated by increasing awareness of subtypes of diabetes in which insulin deficiency appears to be the predominant feature but which present less dramatically than classical type 1 diabetes. Moreover, even the presence of morbid obesity does not guarantee a diagnosis of type 2 diabetes; occasionally, obese patients present with marked osmotic symptoms and/or ketonuria indicative of insulin dependence.

Identification of patients with apparently autoimmune diabetes with a relatively slow onset can be problematic; the prevalence of latent autoimmune diabetes in adults (LADA) is not known but is perhaps under diagnosed (see Section 1). The diagnosis is often made retrospectively (glutamic acid dehydrogenase (GAD) + ve, anti-islet cell + ve) following the rapid failure of treatment with oral antidiabetic agents (see Section 3, p. 97). Useful clinical pointers at diagnosis suggesting that insulin may be required include:

Dietary manipulation ± oral agents may sometimes initially produce dramatic improvements. The issue of insulin dependence is particularly difficult in African Caribbean patients who may present with ketosis, even DKA, yet who ultimately prove to have diabetes that is controllable with oral agents or even diet alone.

Personal telephone contact is best to ensure that insulin treatment is initiated with the minimum of delay.

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