The neurology of non-alcoholic pancreatic diabetes mellitus in Nigerians

Perioperative management of diabetic patients

Diabetes mellitus is the most common metabolic disease. New classifications have recently been proposed by the American Diabetes Association (ADA) and the World Health Organization (WHO). Type 1 (formerly insulin-dependent diabetes mellitus IDDM) is immune-mediated and leads to absolute insulin deficiency. Type 2 diabetes (formerly non-insulin-dependent diabetes mellitus [NIDDM]) is a disease of adult onset and is associated with insulin resistance. Type 3 corresponds to a wide range of specific types of diabetes, including various genetic defects of beta-cell function and insulin action, diseases of exocrine pancreas, endocrinopathies, and drug-induced diabetes. Type 4 is gestational diabetes (Table 1). Diabetics undergoing surgery have increased mortality, and type 1 diabetics are particularly at risk of postoperative complications. Wound complications are increased in diabetics, and healing is severely impaired when glycemic control is poor. However, with the use of modern management plans, the major outcome measures of surgery are comparable in diabetic and nondiabetic patients. Successful management of surgery in diabetic patients requires simple and safe protocols, which are fully understood by all staff and a close liaison among the surgeons, diabetes care team, and anesthetists. There is no consensus on the optimal metabolic management of the diabetic patient during surgery. Several surveys have highlighted the inconsistency with which surgical problems are managed in diabetic patients. The aim of this article is to provide protocols to achieve sensible and practical glycemic control in diabetic patients undergoing surgery.

Chronic pancreatitis and diabetes

Chronic pancreatitis is defined by a persistent destruction of the pancreatic parenchyma replaced by fibrosis. The lesions generally start in the exocrine gland, islets being attacked later in the fibrosis. The two most frequent forms are: 1. Chronic calcifying pancreatitis which is a pancreatic lithiasis responsible for more than 95% of chronic pancreatitis. In its most frequent form, calculi are built up of more than 98% calcium salts together with fibres of a degraded residue of lithostathine, a secretory protein. This disease is related (i) in most countries to alcohol, protein, fat and tobacco and (ii) in certain tropical countries to malnutrition (low-fat, low-protein diet) for some generations. A causative role for cassava and kwashiorkor is improbable. The mechanism of calcium precipitation is partly explained by the calcium-saturation of pancreatic juice and the decreased biosynthesis of lithostathine S, the secretory protein preventing crystallization. As a rule, diabetes (and steatorrhoea) appear after a clinical evolution characterized by recurrent attacks of upper abdominal pain, generally lasting some days with transiently increased concentrations of pancreatic enzymes in serum. When diabetes appears, pain frequently disappears. Complications are mostly observed in the first 10 years of clinical evolution. 2. Obstructive pancreatitis is due to an obstacle (tumours, scars) in the pancreatic duct. It is rarely a cause of diabetes. Diabetes due to chronic pancreatitis is characterized by the low incidence of ketosis and the high incidence of insulin-induced hypoglycaemia. Patients are generally thin. Serum insulin levels, either basal or stimulated, are decreased. Glucagon is less affected. Angiopathies and retinopathies are less frequent than in non-insulin-dependent diabetes. Neural complications are fairly frequent. The diagnosis is generally easy because diabetes appears at a late stage of the disease. The treatment generally requires insulin.

Case-control study on risk factors associated with fibrocalculous pancreatic diabetes

We investigated the relation between fibrocalculous pancreatic diabetes and cassava consumption in a case-control study, in which 31 cases of pancreatic diabetes were compared with 45 non-diabetic control subjects who had no pancreatic calcification. Risk of diabetes was not related to cassava consumption. We also observed no increased risk of fibrocalculous pancreatic diabetes associated with alcohol consumption, history of gallbladder and biliary tract diseases, ascariasis, and family history of diabetes. Lower monthly income, farmer occupation, rural residence, and low BMI were significantly (p less than 0.05) related to pancreatic diabetes. Our data suggest that consumption of cassava may not be an important risk factor for pancreatic diabetes. With limited sample size, however, cassava consumption could not be excluded as one possible cause of fibrocalculous pancreatic diabetes.

C-peptide secretion in calcific tropical pancreatic diabetes

Serum C-peptide levels were measured during a glucagon stimulation test in ten normal nonobese controls and 54 diabetic patients with recent onset of diabetes under 30 years of age. Diabetic patients were comprised of 13 CTPD, 23 IDDM, and 18 NIDDM. As similar to IDDM patients, serum C-peptide concentrations did not rise significantly (P greater than 0.05) in response to glucagon administration in CTPD-patients. Mean baseline and peak serum C-peptide concentrations in CTPD-patients were significantly lower (P less than 0.001) than the values in normal controls and NIDDM patients, but were significantly higher (P less than 0.05) than those in IDDM patients. We conclude that CTPD patients have partial C-peptide reserve, which may protect against ketosis and contribute to ketosis resistance in CTPD. Our results also suggest that CTPD patients require insulin treatment. Neither baseline nor peak C-peptide levels after glucagon could discriminate CTPD from IDDM and CTPD from NIDDM.

Peripheral neuropathy in tropical pancreatic diabetes

Electrophysiological evaluation of peripheral neuropathy was done in 16 patients with tropical pancreatic diabetes (TPD) and the data compared with those of a matched group of 16 NIDDM patients. Peripheral neuropathy was present in 6 TPD and 5 NIDDM patients. Abnormal motor conduction velocity in the lateral popliteal nerve was seen in 9 TPD patients and in 8 NIDDM patients and biothesiometry was abnormal in 7 patients in each group. One TPD patient had an abnormal F wave in the lower limb. An abnormal sensory potential was recorded in the sural nerve in 6 TPD and 8 NIDDM patients. The study showed that occurrence of peripheral neuropathy in TPD was similar to that in NIDDM. Subclinical neuropathy could be detected by electromyographic recording in both groups of patients.

Diabetic neuropathy

Peripheral nerve disorders are important late complications of diabetes mellitus. Polyneuropathy, which may involve varying proportions of sensory, motor, and autonomic fibers, is considered the consequence of metabolic derangements that result from chronic hyperglycemia. Symmetrical proximal motor neuropathy ("diabetic amyotrophy") also may have a metabolic basis. Mononeuropathies in diabetes may have an ischemic or compressive cause. Advances have been made in understanding the biochemical basis for diabetic polyneuropathy. The treatment of symptomatic diabetic neuropathy should be directed toward long-term normalization of blood glucose until more specific therapies become available.

Cardiac denervation and other multisystem manifestations caused by isolated autonomic neuropathy in a young diabetic patient

A young, diabetic woman suffering from fainting spells, vomiting, and diarrhea is described. Extensive investigations showed total cardiac denervation, orthostatic hypotension, and disturbances in the the pupillary and sudomotor functions, as well as impairment of glucagon secretion during hypoglycemia. These disturbances were found to be caused by autonomic neuropathy. No signs of peripheral neuropathy could be detected. To the best of our knowledge this is the second case of total cardiac denervation due to diabetic neuropathy described in the literature.

Diabetic microangiopathy in patients with pancreatitic diabetes mellitus

Clinically evident diabetic microangiopathy (retinopathy and nephropathy) occurred in 18% of diabetic patients with acute pancreatitis and 14% of diabetic patients with chronic pancreatitis. The presence of diabetic retinopathy and nephropathy in patients with pancreatitic diabetes without a family history of diabetes mellitus suggests that these patients have "primary" diabetes mellitus unmasked by the pancreatitis. The occurrence of diabetic microangiopathy is significantly correlated with the duration of diabetes. The frequency of these diabetic complications seems to increase when there is a family history of diabetes in patients whose pancreatitis is simultaneous with or precedes the onset of diabetes. The majority of patients with diabetic microangiopathy were on insulin therapy, but the need for insulin treatment is an indication of the severity of the diabetes, rather than the insulin being a causative factor of the microangiopathy. The degree of steatorrhea in diabetic patients with chronic pancreatitis did not protect against the development of microangiopathy.