Association between caffeine intake and age at onset in Huntington's disease

Habitual consumption of caffeine, a non-selective adenosine receptor (AR) antagonist, has been suggested to be beneficial in Parkinson's and Alzheimer's diseases. Experimental evidence support that ARs play a role in Huntington's disease (HD) raising the hypothesis that caffeine may be a life-style modifier in HD. To determine a possible relationship between caffeine consumption and age at onset (AAO) in HD, we retrospectively assessed caffeine consumption in 80 HD patients using a dietary survey and determined relationship with AAO. Following adjustment for gender, smoking status and CAG repeat length, caffeine consumption greater than 190mg/day was significantly associated with an earlier AAO. These data support an association between habitual caffeine intake and AAO in HD patients, but further studies are warranted to understand the link between these variables.

Insulin and HDL-cholesterol metabolism

Insulin is essential to the physiological regulation of high density lipoprotein (HDL) cholesterol metabolism. It acts directly at the hepatic level by favouring HDL2 to HDL3 conversion (by its action on hepatic lipase). In the peripheral circulation, it induces HDL2 formation by allowing triglyceride-rich lipoprotein catabolism by lipoprotein lipase (LPL) and free cholesterol esterification by lecithin acyl cholesterol transferase (LCAT). In the case of insulin deficiency or peripheral insulin resistance, there is a reduction of HDL cholesterol related to HDL2 decrease, partly due to LPL deficiency. In the case of endogenous hyperinsulinism, there is an intrahepatic disturbance of HDL metabolism partly related to excessive synthesis of VLDL-TG and leading to the decrease of HDL2/HDL3 and enhanced formation of HDL2 TG. When hepatic hyperinsulinism is associated with peripheral insulin resistance, HDL cholesterol decrease is the consequence of both intrahepatic action of insulin and diminution of its peripheric action. Optimized insulin therapy can normalize HDL cholesterol in case of true insulin deficiency. When there is preservation of insulin secretion, HDL cholesterol remains lower than controls. Insulinopenia as well as hyperinsulinism can favour atherogenic lipoprotein disturbances.

[Nutrition survey assisted by computer]

Data processing has made data banks available to the nutritionist, enabled rapid conversion of food data, and supplied detailed even commented listings of eating behaviour. Until now, however, use of the computer has remained the privilege of the dietician. A conversational data programme employing a microcomputer has been developed, enabling patients to establish a dialogue with the calculator, with storage of data concerning their food habits. A double food survey was conducted in 93 adult subjects, one of which involved the dieticians from ISTA, and the other the computer. Good correlation was found between the two estimates of calorific rations (r = 0.84, p less than 0.001) and nutriments. Deviations between the two estimates were less than 20 p. cent in the majority (80 p. cent) of cases. Psychological questioning confirmed the good reception reserved for this type of computerized survey, whatever the initial reservations held against data processing. Performances were not altered by the sociocultural level of the persons surveyed. This type of interactive programme should lead to simplification of the food anamesis, thus favorizing the communication and the counselling role of the nutritionist. It can also be of value in the framework of epidemiological surveys or education of nutrition.

[Dopamine-secreting phaeochromocytoma. A little known clinical and biochemical entity (author's transl)]

The authors have observed a case of phaeochromocytoma revealed by fever and poor general condition without hypertension. Urinary catecholamine assays showed predominant dopamine secretion. Only 13 cases of dopamine-secreting phaeochromocytoma have been published so far, including 4 with clinical symptoms resembling those of this patient. The metabolic and hormonal effects of high plasma dopamine levels were studied, and responses similar to those observed with TRH stimulation by dopamine infusions were obtained: TSH and prolactin responses were inhibited, and GH was increased. This case underlines the need for catecholamine assays, including dopamine, in patients with unexplained fever and apparently non-secretory adrenal tumour.