Blood pressure is generally normal in insulin-dependent diabetic patients in the absence of nephropathy. Despite this, exchangeable sodium is increased. Blood pressure rises with the development of ...incipient nephropathy, and hypertension is common in patients with overt nephropathy. Exchangeable sodium is then markedly increased, but plasma renin is not suppressed. Raised BP in diabetic nephropathy is probably sustained, in part at least, by sodium retention and inappropriate activity of the renin-angiotensin system. There is an increased prevalence of hypertension among patients with non-insulin-dependent diabetes (NIDDM). In normotensive patients, exchangeable sodium is elevated and plasma renin is suppressed. In hypertensive patients, exchangeable sodium is less markedly increased, while plasma renin is again suppressed. These findings are in contrast with those in diabetic nephropathy, and are in keeping with the hypothesis that hypertension in NIDDM is usually due to coexisting essential hypertension. Also in keeping with this suggestion is an increased prevalence of raised BP among the siblings of NIDDM patients. Prolonged hyperinsulinaemia precedes the diagnosis of NIDDM, and hypertension is often present at the time of diagnosis. Insulin resistance and compensatory hyperinsulinaemia might lead to an increase in BP by a number of putative mechanisms, such as enhancing renal sodium retention, by an effect on cell membrane ion exchange mechanisms or by enhancing activity of the sympathetic nervous system. This seems a fertile area for further research, although a causal link between insulin resistance and hyperinsulinaemia on the one hand, and raised BP on the other, remains to be proved.
Noncompliance with medication is common, particularly in asymptomatic conditions such as hypertension that require long-term treatment, and is often unsuspected. We describe two patients with ...refractory hypertension in whom noncompliance was confirmed by a precipitous fall in blood pressure when antihypertensive medications were given under direct supervision.
Some patients with thyrotropin (TSH)-producing pituitary tumors are more hyperthyroid than others despite similar TSH levels in serum, suggesting that qualitatively different TSH molecules with ...differing bioactivities may be secreted by different tumors. We used ricin and lentil lectin-affinity chromatography to test whether the TSH oligosaccharides varied among 12 patients with TSH-producing tumors. We found that each tumor secreted heterogeneous isoforms of TSH that differed in their extents of exposed galactose (Gal) residues, and their degrees of sialylation and core fucosylation. These biochemical parameters also varied markedly for TSH secreted by different tumors. Isoforms appeared to reflect poor sialyltransferase activity in two tumors and efficient sialyltransferase in the remainder. TSH secreted by tumors was more fucosylated than TSH secreted by control euthyroid persons. There was an inverse relationship between the sialylation and fucosylation of tumor TSH. No simple relationship between TSH oligosaccharide structures and bioactivity was evident, although mixtures of isoforms having the least and most sialylated TSH seemed to be the most bioactive clinically. In three patients from whom serum and medium TSH were both available, TSH in serum was more sialylated than TSH secreted by the tumor in vitro, perhaps reflecting slow clearance of sialylated isoforms from the circulation. Core fucosylation of serum TSH was less than that of medium TSH. These data prove that human tumors secrete TSH with heterogeneous oligosaccharide structures.
Premature hair greying has been associated with low bone mineral density (BMD), and it may be more frequent in Graves' disease.
To determine whether premature greying is associated with reduced BMD ...in women with Graves' disease and in control women, and to examine whether premature greying is more common in Graves' disease.
Premature greying (> 50% grey by 40 years) and BMD were determined in 44 women with a history of Graves' disease and 133 female controls referred for routine BMD measurement. Exclusion criteria included diseases or drugs known to affect BMD.
Mean Z and T scores at the lumbar spine were significantly lower (P < 0.04) in subjects with premature greying than in those not prematurely grey among women with Graves' disease, but not among control women. Multiple regression confirmed this difference between Graves' and control women (P = 0.041). There were no differences at other measurement sites. Of Graves' patients, 36% were prematurely grey compared with 25% of control women (P = 0.14).
Premature greying may be a weak marker for reduced BMD in women with a history of Graves' disease, but it is not a marker in normal women.
Sperm-bound antisperm antibody levels were measured in 10 males in subfertile partnerships who were treated with high dose intermittent prednisolone therapy over a period up to 9 months. Antibody ...levels fell in all patients during therapy, although a transient rise occurred after 2–4 months. There were low treatment complication rates. Four pregnancies occurred during the treatment of the 10 patients. There was no correlation between pregnancy and change in antibody.
We investigated the long-term outcome of treatment in 159 patients with hyperthyroidism first seen between 1979 and 1992. Median duration of follow-up was 10 1/2 years. We also inquired into current ...practice for the follow-up of hyperthyroidism by other endocrinologists in Ireland. Seven cases of unrecognised hyperthyroidism (4 per cent) and one of unrecognised hypothyroidism were identified. Among patients with Graves' disease, of those treated with an antithyroid drug, 28 per cent were in remission, 68 per cent had relapsed and 4 per cent had become hypothyroid. Of those treated by sub-total thyroidectomy, 31 per cent were in remission, 19 per cent had relapsed, 19 per cent were hypothyroid and 31 per cent were sub-clinically hypothyroid. Among patients treated with radioiodine, 19 per cent were euthyroid, 3 per cent were still hyperthyroid and three-quarters had become hypothyroid. In contrast, after radioiodine for toxic nodular goitre, 63 per cent were euthyroid and only 32 per cent had become hypothyroid (Chi Squared v. Graves' disease, P = 0.001). Of 73 patients receiving thyroxine replacement, plasma TSH was normal in only 41 per cent, although 82 per cent of patients had been seen by the family doctor within the previous 12 months. Seven of 17 other endocrinologists undertook long-term follow-up of hyperthyroid patients in their specialist clinics but none was using a computerised system to co-ordinate this. The findings confirm that careful follow-up is required for all hyperthyroid patients. The family doctor is well positioned to undertake this, but education and auditing are required.
To examine the relationship between smoking and both glycemic control and microvascular complications in patients with insulin-dependent diabetes mellitus (IDDM).
This was a prevalence survey of ...3,250 men and women aged 15-60 years with IDDM from 31 diabetes centers in 16 European countries. Participants completed a questionnaire, had retinal photographs taken, and performed a 24-h urine collection. HbA1c, frequency of hypoglycemic and ketoacidotic episodes, urinary albumin excretion rates, and retinopathy were compared by smoking category.
The prevalence of smoking was 35% in men and 29% in women. Current smokers had poorer glycemic control and, among men, were more likely to have had a ketoacidotic episode than were those who never smoked. Ex-smokers had equivalent glycemic control and marginally more hypoglycemic episodes did than those who never smoked. Current smokers had a higher prevalence of microalbuminuria and total retinopathy than did those who never smoked. Ex-smokers had a higher prevalence of macroalbuminuria and proliferative retinopathy than did those who never smoked, but both had a similar prevalence of microalbuminuria. Adjustment for either current or long-term glycemic control could not fully account for these differences.
Smoking is associated with poorer glycemic control and an increased prevalence of microvascular complications compared with not smoking. Ex-smokers can achieve glycemic control equivalent to and have a prevalence of early complications similar to that of those who never smoked. We suggest that poorer glycemic control can account for some of the increased risk of complications in smokers, and that quitting smoking would be effective in reducing the incidence of complications. Urgent action is required to reduce the high smoking rates in people with IDDM.
A 23.5 GHz 32 nm SOI-CMOS PLL with 30% frequency tuning range features an adaptively biased VCO. The adaptive biasing scheme lowers the average PLL power consumption from 34 mW to 27.2 mW, while ...keeping the jitter below 1.3° RMS across all frequency bands.
The prevalence of hypertension was investigated in a systematically chosen sample of patients attending a diabetic clinic. One hundred ninety-one patients were classified as Type 1 ...(insulin-dependent), 183 were classified as Type 2 (non-insulin-dependent) and 12 were deemed unclassifiable. Two hundred fifty-five control subjects attending non-medical out-patient clinics were also examined under similar conditions. Hypertension was significantly (p less than 0.001) more common among Type 2 patients (38%) than among Type 1 patients (15%) or control subjects (16%). The difference between Type 2 patients and control subjects, but not between Type 2 and Type 1 patients, persisted when the influences of age and body mass index were controlled. We also investigated the prevalence of hypertension among the siblings of the hypertensive patients identified, together with a matched normotensive group. One hundred eighty-eight siblings were examined and historical details were obtained for a further 451 siblings. When age and body mass index were controlled for in examined siblings, the risk of hypertension was greater in those with a hypertensive proband than in those with a normotensive proband, in the control (p less than 0.06) and Type 1 (p less than 0.02) groups.
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